Yeah mate if you go zvh you can use most things the best person to speak to (in my opinion) is simon from sitech he will be able to supply you with everything you need my brother has not long changed from a cvh to zvh and the differance is awsome.

He has changed a few more bits though but it was worth it
2.1 zvh cosworth racing pistons
Stage 3 ported big valve head (soon to be ported some more)
cosworth sweedish inlet modified to fit
deka injectors 650cc (i think)
TT T38 turbo
Haltech mangement
cant remember anymore but it has made 334bhp so far at 21 psi