If drifting is your main focus, neither of those turbos will be any good at all.
Too much lag and not enough response, peaky power delivery and poor throttle adjustability (important in a drift car!!!)
A few of the (expensive) parts/mods on your list would be over-kill for an RB30DET built to make a nice, responsive, 450 to 500hp- which would be more than enough in a light drift car like a silvia with the right suspension set-up.