A turbo will definetly give the highest numbers once you get into the multiple 1000'* of dollars. You will need to find someone who can tune for your PCM setup.
Fabrication will also need to be important. Just welding a turbo to std manifolds isn't good, they need to be BUILT.
Turbos do not have to be "laggy" either. Properly sized housings and turbines are key to any good setup...
I wouldn't do a custom turbo setup unless you knew what you were doing with everything. Read up in books if that'* what you want. The pre-fab kits are good for 3800'* but only for S2..
'06 Vee Dub GTI 2 door Tornado Red
- 2.0 Turbocharged, Intercooled, Direct Injected, 6 Speed DSG, Underbody Aero, 17" Classix
- Moonroof, Bi-Xenon headlamps, Interlagos Plaid Sport Seats, 6 Disc In-dash, iPod integration, GTI Monster Mats (winter)
'93 Bonneville SE Purple Pearl H4U package - picked up June 23, 2003, Traded-in June 28, 2007...