Tim,
In Hawaii we don't have the roads to open up the engine and use the high end (safely). I'm running around 550 WHP with two small turbos and a set-up to maximize low end. Even with that, I think Oahu roads, and traffic, are better suited to a car with better low end even if you sacrifice some top end. I would consider a SOS supercharger with or without a big bore rebuild.
Contact me and I can give you a ride.
I sent you a PM.
Steve