Compomotive ML's 7x15. I'd suggest buying a mint 1.6 laser as your base if you go the mk3 route - hunt around and find one that's been stored. The best of the best should be around £1,700. I would suggest places to look for rust - but it can be simplified to EVERYWHERE!! Rotboxes are all over the place, so take your time looking for the right shell, it will save you ££££ in the long run.
They sure are.
Two areas I'd suggest you definitely check batman, because we spent a lot of time and money buying and welding new panels are:
Front suspension top mounts. lot's of capri's have repair plates here.
Door hinge panel on A pillar. The first sign is the doors drop and it sounds crunchy, this is a tricky repair.
I think the front wings are spot weld on, not bolt on like the ford cortina mk3/4/5. One tip I suppose, when we replaced them we drilled them and used bolts so we could remove them easily in the future.
Like the man said, if you are going to put a big engine in anyway get a 1.6. they are usually cheaper than the v6's.