ah... so basically (let's see if i got it)
if your civic is OBD1 (92-95 5th gen???) then you should, for simplicity's sake, swap in the 94-95 B18B.
If your civic is 6th gen and up, then it would be OBD2 and you should swap in a 96+ OBD2 B18B...
so you're sure there are no advantages of either...