What is the best route. My plan so far was to leave the car OBD2, by adding the H22A4's OBD2 emissions parts, and sensors to the H22A. Crank sensor, distributor, alternator and so on. Is this the best route or should I go OBD1?

 

slow down there big guy.
you're over complicating it.
Since you already have an H22 to start with, it makes things easy.
I just put an H22a short block in that replaced a friends H22a4 block.
The plugs for the knock sensors are different, so you'll need to swap over the obd2 knock sensor. Aside from that, use your original distributor and intake manifold and you'll have to put on an obd2 oil pump so you have the crank angle sensor.