If you get a USDM b16a2 swap, then you need to wire up the o2. Might need to run the vtec wires. You need a obd2b-obd2a harness adapter. You need cut and splice some of the harness plugs from the USDM b16a2 harness to your civic harness.
You can get a obd2 b16 from a 96-97 Civic from Japan. Then you will need to do everything I just listed, except the harness conversion (i think).
You dont hear anything about ppl getting 96-97 obd2 b16's from Japan. Your best bet is probably a USDM b16a2 (99-00Si)
I am sure there is more, I just can't think right now.