The answer to all of these is yes - but.
I am unsure whether the 22RE inlet manifold fits, but i doubt it does. Measure it up and compare, but you'd probably be better off having something made up.
I suggest going aftermarket management, there is NO point in using the 22RE computer.
Basically i am suggesting a full custom job. Even if you used all 22RE gear, it would still be slower than your twincarb 18R-G, as nothing would be set up right for it. Oh, it'd redline at 6.5k or thereabouts too.
Pm me if you with to discuss it further.