This is a how long is a piece of string question.
Starting with the front corners:
Uprights - Many will say chuck the old ones as a matter of course and replace them with new. There is some sense in this, but at the very least check that the threads on the bottom are not damaged.
Stub axels - should be OK, but often arn't. Check they are not scored, or blued by the bearing turning on the shaft. If you arn't sure chuck them, they are cheap as chips. That said, new ones often have poor quality machining.
Wheel bearings x2 each side, Oil seals each side. TR6 fitting, but don't buy the cheapies from E bay (or indeed many Triumph specialists). Get Temkens or similar quality. Yes, I know they will cost about 3X as much.
Consider discs too, after all, the whole suspension is in bits. There will never be an easier time to do the job.
Steering arm - Pray its OK, because you cant get them (having said I think that new hand made ones are available from one Lotus specialist).
Speaking of brakes check and refurb your brake calipers - If they are suspect, or siezed, its just as cheap to get your old original ones refurbed by BigRed or similar as it is to buy a Chinese import.
If you are redoing the suspension then trunions each side as a matter of course.
Top swivels, check for play, I believe they are TVR specials but available through speicalists.
I would also check the track rod ends, but beware, TR6 spares suppliers are currently supplying some pretty crap TREs which have been known to last <6m on the car without the boot perishing. Find a supplier of decent ones, or you will be doing it again before the next Controle Technique.
As far as bushes go, this is really a matter of personal choice if its a road car. Polybushes are expensive in comparison, but if you are one of those people who like to "press on" then maybe you should consider it. I may not have bothered if they didn't come with the car. Some people swear by them some say that its hard to tell the difference unless you are pushing the car very hard.
Rear suspension, well, there is a thread running right now all about that, but in summary
Dismantling is realtively straight forward, Get decent bearings again. Repacing the bearing shells can be a specialist job and doing the crush tubes is something worth researching. You will need new oil seals X2 each side)
I think Ive rambled enough now. I ll leave it to the experts, finally, Vixen parts list here in case you weren't awarehttp://www.zen11896.zen.co.uk/vixen/parts/index.ht...