I believe the crx si rear discs are smaller than the integra... not sure.
Yes, I believe you need the prop valve.
Ugh... I wish I had my crx still. At least I'd be able to take pics and post up what it all looks like even if I didn't drive the car. And based on the examples I've been seeing lately, I wish I had kept it and just redid the suspension, driver side rocker, fender, roof (maybe glass top) and painted. Hell, I'd probably even have a b-series by now...