as said, get something that is pretty standard, maybe a few choice mods, then spend some cash getting the power up.

the biggest issue and cost with any rs is bodywork. So get the cleanest example you can and go from there mate.

Check out the rsoc website, pistonheads, here and similar sites and see what is about.

No good asking people to find you a car, hundreds for sale, but you need to find the one you like.