depends on what series your going to compete in.. that's if you are though..
if you just want a weekend track car.. something with replaceable parts would be much better... KA-T.. SR20.. VQ.. and the bandwagon engine LSx...
using a LSX is great.. for drifting u can bang the limiter all day and not give a shit lol...
as far as using the RB20/5/6/30 it would make great for a TIME ATTACK car... if u had shit ton of money to throw around.. it being nose heavy is something that can be made up for... i actually like a lil nose heavy
plus having more torque out of a corner is nice..