The old bodies can be used on the new cars. You'd have to look up which car uses the long chasis that the skyline does. I believe the firebird would work (and it's cheaper), but double check.

As for the evos, there really isn't a difference performance wise between any of them.

I agree with the hummer, I don't like mine either; not to mention the body is much heavier than the rest. I do like the truck chasis though... my upgraded one was a lot of fun to drive. Namuna's hummer on here is pretty sick.