Assuming that you have all the maintenance up to date(fluids, brakes, suspension etc), that the exhaust is at least 3 inches from the cat back and everything is in good condition...
As stated above, either drill out or remove the stock boost restricter. Will net you 12-14psi.
I would suggest you get a nistune board installed in you stock ecu. It will be cheaper and arguably better than a PFC.
As a preventative measure, I would invest in a new fuel pump too.
From there.... how fast do you want to spend/go?