For doing the lining-up on a project, but don't want to spend much right now, prefer to collect crapped stuff off peeps for free (yes, I'm cheap ), but I'm quite prepared to cough up a few quid depending on the item.

Definitely needed :
T5 Gearbox.. casing, screwed box, whatever.
T5 Gearbox mount.
205/200 Block, knackered or stripped.
Engine mounts for above, 2wd/4wd
Engine 'cradle'/front mounting beam for above, 2wd/4wd.
Cosworth head, again, anything that's cream crackered.
2wd/4wd rear diff casing, or shot diff.

If they're free :
Shagged steering rack
Front wishbones
Front anti-roll bar
Front struts

Preferably NW-based...