You're in luck, as the admin (Rob) of this forum is pretty familiar with the RWD SR20DET combination. You can always use your existing wiring harness, it just depends on how much splicing you're up for. As for a direct fit, I know Rob makes loom adapters for the S13/S14 crowd, which may be possible for you as well.
Personally, I had to make my own adapter (FWD SR20) but was able to buy the Nissan ECU plug from Rob.
If I were to do it over again, I'd make my own wiring harness in a heartbeat. We did that on Dan's BMW and it worked out much better.
As for the control of boost... That is easily done with VEMS and an electronic boost solenoid.