i'd have a mk4 as a daily, probably have a mk2 as a "toy" car, oak green, big bumpers, keep the 16v engine, always liked the inlet manifold

mk4's are getting on for 10 years or older, so bushes will need doing on any car,
mk2's are probably better round the corners on the limit, but i found my mk4 to be easy to drive fast, if not flat out.
@ motorpsycho if you do the servicing and maintence yourself, only the parts would be decisive, i haven't found the mk4 to be that expensive for parts, i guess a mk2 is cheaper for parts being older, and having next to no sensors