stock boost on my silver top rb20 is 10psi. the R33 runs about 7-8 stock.
with the turbo, its really upto you how you go but i think that the GT series turbo would be better cause its ball bearing and it will spool better on the Rb20 giving better response down low.
how you thought of getting a silver top head and putting it on your block? i have one and sold it to a guy in the same situation you are in now. they flow better too.
GTR cams, gears, and injectors are another good idea as well, the valve springs you don't really need for 200rwkw.
anyway yeah, whichever way you go its sounds like a good project