Adam- how about twin-turbos with sequential engagement that. That way you have low-end boost/torque, and then have the second one come in for high-end boost.

Did you read the article on the twin-turbo C36/M104 engine? I would that many of the issues here would pertain to your setup.

Check it out here:

http://www.silcom.com/~neilv/C36turbo

:-) neil
1988 360TE AMG
1993 500E