Improving the ride

[Sheffield]

We have a MK1 Cooper with Chili pack, 17" alloys, and Pirelli Eurforia run-flat tyres (all quite new).
We have had it for a year now and love the car, but it has a tendency to tramline a bit and the ride is quite harsh.
Its great fun to fling around but i am wondering if we should sacrifice a bit of this for a better ride.
What are my options?
I have throught about fitting 16" Alloys and non-run flats, or will just fitting non-run flats to the 17" alloys make a significant difference?
What about changing from 205 to 195 profiles?

Your thoughts would be appreciated.

[Sheffield]

Thanks for all that.
So most people stick with the 17" alloys and just change the tyres.
Its a shame they are nearly new run flats on it at the moment...

Do you also stick with same tyre size or has anybody moved down to 195 instead of 205?