Oversized valves and procams are not needed. Stock cams will make 350kw atw's no problem. Injector dynamics 1000cc injectors over the 850cc.forget the twin thwrmo's on the radiator and stick with the stock clutch fan and stock Nissan surround. Cam gears are good and atleast a 3.5" exhaust. If it were me I'd sell the the r34 gtr turbos and buy some -5's . If e85 is available I'd be going with that as well, make more power easier and SAFER. if you can afford forget the power fc and go a adaptronic/vipec. At that power level you'll need to look at a NPC clutch as well. No need for boost controller. A good ecu will do this.
Ps. There in tonnes's of info on here for your goals do some reading.