Quick noob question

I have a 90 ef hatch dx standard d15b2 dpfi. I want to put a jdm d15b with a y8 head vtec. I'm getting the complete swap. it's out of a 99 civic I believe. what do I need to get to go from obd-0 to obd-1 and still run this obd-2 setup. will obd-2 cancel out with an obd-1 harness and a chipped p28? can I leave my inside harness alone? I'm picking up the motor tomorrow so any answers would be much appreciated.
thanks
chad