Your going to need need clutch. Stock clutches are terriable! As far as low compression pistons
Don't even try and boost a GTS without them.. And Rods! Crower Rods and Wisco Pistons!
As far as running 300whp plan on really spending some money. C2Gas or bling from N C.org blew his transmission at 18psi. Your gunna need new gears if you boost that high.
Bigger fuel injectors
Larger Fuel Pump
im guessing you ned a CAI because the intake for the turbo goes where the short ram one goes
Thats a negitive! You can do a custom CAI
but there was a post abit ago (Search Button) discussing CAI
on turbo's. As far as investing into one, I've read your better off keeping a Ram air.
No the turbo doesnt go where the Intake
The turbo goes off the manifold and the manifold is located in the back of the engine. Follow your exhuast! lolz
Anways. Your Intake
shouldn't be a problem. As far and finding all the parts might be.
I recommend getting a kit. But if you do custom do it.
Your gunna need FMS too.. Along with countless other things..
Hope I helped