Hmm, are you ever going to want more than 350? Because you need to build around the turbo sizing. FP Green could get you to 400 pretty easily. But there's loads of turbo choices. Think someone did a thread in the general Subaru area with a list?
pistons & rods, Weisco pistons, Carrillo Pistons and rods or Eagle rods? ARP if they make them? Maybe check into head studs etc as well.
Injectors at least 800cc probably 1000 I'd say, RC Engineering does good ones.
Bearings, Clevite (spelling?) do the ones for NASCAR so they're good. Or there's good ol' ACL as well.