As far as B-series gom GSR if youve got the money, B16 if you have a liiiittle bit less and dont mind 111lbs of torque. There are alot of options though... many swear by B18Bs, B20s, and LS/VTEC.

oh, and your swap wont HAVE to come from an OBD2 donor, but it will be ALOT easier, trust me. its always a good rule of thumb to swap OBD1s to OBD1s and OBD2s to OBD2s.