what do you plan to do with the car? thatll decide what you need as far as gearing goes. If you want a drag car, 5 spd. If you want a road racing car, 6 spd. Daily driver with highway runs, 6 spd. Autocross car, doesnt really matter, as youll only be using 2nd gear anyway.

The main difference will be, youll get pretty much the entire drivetrain from the STI for what the PPGs cost. The PPGs will only get you the gearset, and youll still have a weak differential.