differences:
Well the tranny is different. 92+ b16a2/3 trannys are hydro clutch type 89-91 b16a1 are cable.
head is different. Better cooling in 92+ better intake manifold and throttle body in 92+ better cams higher comp ratio if JDM.

If it was me (actually this is what I did) Id get the b16a1 and run that. With the $1000 you save build a 1.8 block or save for turbo or whatever. Pretty much any of the things that are not as good on the b16a1s can be replaced directly w/ ITR parts and run alot better anyways.