Blimey,where to start..
First off,as usual,drive a Rover and Toyota engined car to compare the experience.
The Toyota engined cars have ABS as standard,traction and a/c were options.Rover cars had no ABS or traction,a/c an option.
Make sure you both get driver training as no amount of safety gubbins will stop you ending up in a hedge if you go too mad

Hard tops were optional too i believe on both yota and rover cars,look to pay £500-700 for a second hand one if you want one.
Sounds like you should get a later 111R,£15k should get a fairly decent one,look to spend a bit more for an 06 model year(has better pedal box,revised dash,led rear lights etc)all IMHO of course.A friend has a 111R that he uses as a daily driver and its been faultless,he gets the servicing done at an indy for very reasonable money.

Service intervals on the yotas are 9k miles/1 yr,with a basic service costing around £200.
As for reliability,the later cars always seem better screwed together and the yota lump is pretty bullet proof.Dont discount the rover engined cars as you might like them better,they're not as bad as some people make out .

My car has just done 2700 miles around Europe without any problems and has done 5 trackdays this year already(last one being Spa).
New set of tyres (£450)and pads(£100)after 12k miles of road/track use.

Had no problems with leaks but then mine is only 20 months old,its not generally a problem on later cars
Mileage wont be a problem provided suspension refreshes and maintenance has been regularly done.
Phew,hope thats covered everything.Have a look here for more help: http://wiki.seloc.org/a/SELOC_TechWiki

The Elise is a brilliant car but it's a bit hard core for a daily drive IMO unless you are fairly young and without a family. If you dislike unreliability, get a Yota engined car. The Rover isnt that bad an engine but it does need looking after and is very prone to head gasket failure.

The rest of the car is simple. Hoods on mark 2 are quite good but no softop is ever totally watertight. The chassis is glued together aluminium so you need to make sure that no one has bodged a repair to it. The chassis cannot be repaired after significant damage because the adhesive used is heat cured in an autoclave. Trim and accessories are of mixed quality but then it is a small volume hand made car so dont expect BMW level of sophistication

Sorry guys but you just seem to be repeating the ill-informed 'views' held by those with little or no experience.
At 52 I'm into my fourth year of Elise ownership and have covered 35k miles in the car in that time, about 50% of that time as my only car and daily driver.
My car also has the supposedly unliveable with close ratior gearbox and has Nitrons with much, much firmer springs than standard. Is it uncomfortable? No. Is it unusable on Mways and for long journeys? No - I've done loads of 300+ miles jaunts. Is it unreliable? No - totally reliable in my ownership. The car is happy to be thrashed round a track all day and has always got me home (often over 300 miles away) comfortably and safely.
HGF? You may be unlucky but get the repair done properly (liner heights checked, firing rings checked over and head hardness tested) and it shouldn't happen again. Anyway, if the engine goes bang, K series engines are pretty cheap to replace.
At £10k buy a good S1 and look for regular oil changes and when the cambelt is due. If the car is much over 50k miles then look for replacement suspension bushes, balljoints, TREs, steering rack (replaced or refurbed), dampers replaced. Ignore traditional advice about tyre wear patterns; odd tyre wear on an Elise could just mean the adjustable suspension geometry is out or that its been set up to suit the owners handling tastes.
You really need to try different cars before committing to buying though: All varients of the Elise are basically the same but different and we all have our own favourite.

I am on my 3rd Lotus - a 111R. Previous Loti being a standard Rover engined S2 (long roof) then a Toyota NA Exige. All cars are and were used as daily drivers in all weathers, left outside.

I had no serious problems at all with my first Elise other than the altenator giving up - which is common on early Rover S2's due to the heat build up. Cheap to fix though. The car never leaked, ran well, didn't eat tyres and was all things being equal, cheap to run as a daily car (I am over 40 so insurance not a problem either). I did 18k in just under a year before chopping it in on the Exige.

The Exige was a superb car. Loads of grip in the dry. A few track days in the UK and abroad. Trip to Le Mans. Had the car just under 2 years and put 28k on it. Car didn't leak and was ultra reliable. The technical issue I had was returning from holiday the car had been standing and the ECU went into emergency mode due to the damp getting into it. A quick clean and drying with a hair dryer sorted that. Tyres (A048's) were costing me a fortune with the rears last a little over 5k - less with track days. So had to get shot of it whilst my mileage was increasing.

My current 111R (touch wood) is probably the best all round Elise / Exige for my purposes.
No hardtop - as I have to roof off as much as possible all year round.
Maintenance is purely regular services which run around GBP250 and I have just replaced the tyres and brakes all round which was expensive.
The wife and I have just done 3,500 miles touring Germany, Italy (Stelvio of course), Austria, Hungary and Poland. The car was faultless, perfectly comfortable for 500 mile trips with some stops of course.
The car is used everyday for my 70km commute.

Yes I have air con but also have a roof that comes off and windows that open - if I didn't have it I don't think I would miss it - although it is handy for demisting the windows in the colder weather.

For more info and to join a friendly bunch of people goto the Midlands Lotus Owners Club (www.mloc.net or www.midlandslotus.co.uk) and ask around on there. Someone will be more than happy to meet up with you and help out.

Oh - and of course the best colour as anyone will tell you is Norfolk Mustard preferably with Lotus Green stripes

I decided a 111R was the right one for me as well after several years with Civic Type-Rs. I've had mine since February and covered 11,000 miles. It lives in a garage but doesn't leak, has suffered only very minor reliability issues and is generally a most loyal friend. When I was looking, £15k would only get a fairly ropey example, but if you can stretch your budget you should find a very special car which you will adore. Best of luck and enjoy it!

I looked at one which was up at £16,500 and it was awful - obviously lived outside, paint bubbling, the seats were dreadful, trim was damaged, etc. They're not mass-produced cars and still quite fragile, requiring plenty of TLC. My personal preference was for one which had the Probax seats as these seem considerably better, but everyone has different priorities.

I would recommend trying to get an MY06 car. As stated above these have the LED rear lights (which look better), probax seats and are generally put together better. They also have the updated pedal box (a must) and fly-by-wire throttle (probably not such a benefit).

I ended up with private sale, but it had 2.5yrs warranty with TWG and I had it inspected by a dealer as well. Touch wood it's been fine with just an electric window fault and replacement track rod ends required during 11,000 miles. The bills are higher than running my Civic and I'm mighty glad to have my little Clio to park on site and around town, but the Elise is such a perfect companion for the business of driving. I got up early on Sunday just to go and have an autumnal blast around the lanes while it wasn't raining. Absolutely brilliant fun.

Mine is a K-series (Rover) engined 2003 standard model (120bhp), I drove the Toyota engined Elise, but found power delivery too peaky, I found the k-series is much better in mid-range torque (this could be down to the aftermarket exhaust added by a previous owner though) anyway I found it a more enjoyable car to drive on the road.

Mine is a second car and see's 5-7000 miles per year, it sleeps outside for the moment (trying to remedy this) but I've had it over 2 years now and no problems so far (touches wood). I wouldn't pay much heed to the stuff that gets spouted about the k-series, if you know what to look out for you'll be fine.

One thing that does irritate me is waiting for the engine to warm up, I generally allow 20 minutes of tame driving before I go over 3000rpm to make sure the engine is warmed through. Of course you don't have to do this but I'm quite mechanically sympathetic and hate revving a cold engine.

I've done 430 miles in a day without leaving the car, petrol and toilet break excepted and it was no more tiring than any other long drive, in fact it was more enjoyable because of the elises unique appeal.

The hard top is expensive, I have one but it sees very little use, I am considering selling it in fact.

This site is fantastic for finding info, and most of the owners are only too happy to help.
Other useful websites I've found are:

Elises.co.uk
eliseparts.com
hangar111.co.uk

Hope this helps, any further info needed, just ask. P.s. you won't regret it, they are incredible cars

Seriously,have a drive in a yota engined S,you'll get a newer car for the money and its still a very capable little car.
I did'nt really enjoy the power delivery in an R,the S just seemed more accessible and damn near as fast(up to silly speeds).
Horses for courses,so the best advice is to drive them all and make your own mind up