You could run that up to about 7 or 8 psi. It's a good kit, but I've heard bad things about the wastegate that comes with it (delta gate or T'netics). I believe that the DRAG kit is also a Turbonetics turbo which I've also heard bad things about.

I'd lean more toward a MaxRev, RevHard or Precision setup. They're better kits and come with better parts.

Lemme know if you need pricing.