alot of people have boosted the 420a engine and they can be plenty quick, there are kits out there that are pretty much plug and play. just make sure to keep the boost relatively low if your planning on running stock internals 7-8 psi. and you are going to need some larger injecters and a bigger fuel pump as well as something to tune with like DSMLINK. you could probably get away with untuned but always better sfen than sorry. check out
www.dsmtuners.com lots of good info and helpfull people on there.
peace