i use an SIP twin hammer one, got it for a bargain at £130, composite body very good unit, but retail was something really daft like £300.
ingersoll rand was the other i was looking at, just couldn't find a bargain at the time.
ultimately make sure you have good feeds, my tank has a crap built in reg that seems to drop flow very quickly and potential on my gun isn't even close where as on a good compressor setup there is nothing it hasn't done with it's 800lb/ft nut busting ability.