Trygve,
Why dont you do youself a HUGE favor and keep your Very nice street car as is and buy and already totally preped Arena Red Spec Box that has a great track record and every possible "legal" Spec Boxster option. this is one of if not thee best builds out there as of now. I have just the car for you and might even consider your car as partial payment.
Give me a shout if your interested.
Tim
443-834-9620