Turbocharger options depend heavily on final power output required by you. Consider this very carefully as your engines:

Bearing clearances.
Bore Clearances.
Compression Ratio.
Ring pack Gap.
Camshaft Kit.
& Turbo charger.

Will all be specced to ultimately suit this end result. Try to get it right NOW rather than compromise later.

As for powder coating, maybe Ask Daz where he got his done as i think it was pretty good quality and a decent colour too