you wanna stay on stock turbo and make as much power as posible that is what I am getting out of this post. Well here is what I would recoment since you already ordered downpipe, catback and ap2. Upgrade your tmic is a must, I would also get a alky/water injection kit, upgrade your boost solenoid, or get a new uppipe that is flanged for external wastegate and get an external. you don't need to upgrade injectors, or fuel pump with the stock turbo. The biggest problems you will run into is being able to run some timing because the stock turbo makes huge midrange power, then drops off around 5500. The water, alky, meth injection will allow you to run insane amounts of timing safely, with as much boost as the turbo puts out, and the reason I say external wastegate is because the stock turbo is going to spike boost in 3rd 4th & 5th gears in the low mid rpms, I have hit 24psi in 4th gear @ 3400 rpms on an incline. An external wastegatge is going to allow you to control your boost alot better, you will be able to eliminate the boost spikes and also boost creep. the talk about p&p stock header and uppipe in my opinion is not worth the trouble when you can just buy a header already done, which will yeild some power gains, but not much on the stock turbo. When you upgrade turbos that is a different story. I am speaking from experience as I have done everything motor wise needed to make as much power from stock turbo as you can on my 07. My car has not been stock since 12 hours after I picked it up and I have been building and tuning cars for 11 years. If you need any more info PM me and I can give you more details and what to expect from your car.