I've got a VF29 right now. Its very very small (essentially its a VF30 with a smaller compressor side).

Actually Milo got one for $200 I believe from Doug's STI at ********.

A VF39 is still a good upgrade over a stock TD04, especially for that cheap.

All the IHI turbos make within 30whp of one another and spool within 500 revs of each other so comparing one to another is kinda pointless. Even the "huge" VF22 only spools a couple hundred revs slower than the "quick spooling" VF34.