engine build recommendations

[Zodiac]

ok so as we get closer and closer to the release of the 818 I really need to start ordering stuff and putting things together. I'm going for about 350-400whp myself. Probably not all at once but the engine internals I for sure want to get done so I don't have to worry about taking the engine out and apart later down the line. I've read and looked up a lot which has helped me make out my list below but still have a few questions.

Engine
• GSC S1 cams w/ upgraded valves and retainers
• ARP Head and Case Bolts
• OEM 79mm crank
• Manley H-Beam Rods w/ Manley 99.5mm STD pistons
• ACL Race bearings

Other
• Blouch TD05H-18G-XT Turbo w/ 7cm housing
• ETS Top Mount Intercooler
• Perrin Inlet Hose w/ Intake Filter
• Deatsch Werks 850cc Fuel Injectors
• Walbro Fuel Pump 255Lph
• AEM Wideband o2 sensor
• Gruppe-S Unequal Headers w/catless uppipe

So givin all that I'm mainly wondering if I really need to go with a nitrided crank or am I ok with the OEM one (150k miles on donor or new OEM)?? Also the Blouch Turbo comes with a turbine housing options of 7cm, 8cm, or 10cm so really not sure which I should go for. Block is getting honed and probably decked but do I need to get the heads ported? And any other help is greatly appreciated.

Hopefully this could also help anyone else looking for answers to build question/decisions.