To me the spirit of a GTP comes from it being supercharged. Plus I have absolutely no knowledge of turbos. The only things I have ever heard about them is how much of a headache they can be.
I'm assuming that by adding this $2400 turbo kit and getting more boost than I can get with a intercooled supercharger that I would have the exact same issues as I would with having too much boost from a supercharger. Think about this, I could Whipple charge it and get way more performance than a basic turbocharging kit, but then again that would be more money yet. It just depends on how much money you want to spend and I'm not willing to stick all that much more into this car. There are plenty of N/A cars that will smoke turbocharged and supercharged cars. Its not like its impossible to have a mean GTP without going turbo. I'm not looking to stomp every single car I run into. Thats stupid to think that you will unless you have some unlimited source of money or plan on building up your car over a period of 20 years.
In addition to that whats the point of having a GTP if your not gonna have it be supercharged?
You could buy like 10 of these cars for how much it costs to whipple one, just stick with the M90 if you don't want a turbo.