ecu question

another question i have a 2000 si b16a and i was wondering if any other ecu from the junk yard or something (or type r,gs-r,etc) or anyting would give me some decent power gains without havting to splice it into my harness is there any that i could simply unhook and hook up thats would do this if not what kind of ecu is pretty good one (not necessarily a stand alone ) maybe a remaped or something that will provide decent gains any info would help