i think u will need a twin blown setup, and getting the parts is not a problem bro, i think building ur block and internals are the main point to achieve a high horsepower engine with good durability, make sure u send ur block for machine before forging the internals, make sure ur piston to wall clearance, bearing clearance, balancing and all this is a must if u want ur engine live longer, u can achieve 500whp no problem to to maintain that long, err haha
and rather then worrying about turbo, i think u should worry more on management, injectors, pumps, and tuning.
im rebuilding my engine soon too, and we could share knowledge and build it together if ur interested
hope our abg jinkl can have a lecture class for us
and bro do it slowly, dnt rush, if ur not driving the car always, leave it for couple of weeks or months, do it nicely, make sure everything is ok and good
for workshops, u can always go for joshua, toby or kamal pulse...
and if ur in a budget, u can always find me for some reasonable price products