B18A1 Turbo Head Gasket Q's?

Ok so im 99% sure my head gasket is going/gone... White exhaust valves, (not running lean, running rich) loosing coolant, and lose of power. Not smoking white yet... My question is what head gasket should i get for a turbo B18A1 that will hold the potential for 400+ hp? Should i get ARP head studs or just get OEM? Any info is greatly appreciated.
Have the head pressure tested and resurfaced first, ensure the sleeves are not cracked, clean it all up, and ARP's and a OEM gasket to seal her back up. Don't put that copper spray shit on there.
Going to have head port and polished and 3 angle valve job, new titanium retainers and springs, camshafts, valve seals, conecting rods and pistons, t-belt, water pump all seals and gaskets, EXT. Should be a fun car afterwards.