TrueEm1

Okay so I've recently acquired a 2000 SI em1 obd2b. I've never dealt with obd2 a or b before so I really didn't know what I was getting into. Here's the situation
I got it with an obd0 jdm b16a SiR 1 long block but it has an obd2b dizzy obd2b throttle body with obd2b injectors and a 99-00 civic sir hydro s4 usdm trans.
I got 4 harnesses thinking obd2 was obd2 and it was that simple. Now I'm in obd hell.
So I got a headlight harness which is correct, a main dash harness (floor cabin harness) that said 99-00 civic on eBay which ended up being obd2a, the harness in the dash that the cluster connects to is obd2b. And my brother gave me an obd2a engine harness that he fabricated that plugs up to everything obd2b on my engine but has obd2a Ecu plugs.
I guess what I'm tryinna ask is how the **** am I gonna make this **** work? I have extra sets of every harness, so I have enough plugs to 're pin everything if needed. I just don't know where to begin pinning what to what.
Any information will be appreciated