you can get a properly set AWD sideways, and then stand on the gas to straighten out the turn exit. Very cool. highly addictive.
But RWD is almost as fast around turns with the proper driver, and it's almost always faster off the line for a comparably powerful car. The big three drawbacks for AWD are weight, complexity (more wear, more break) and lower mileage. Having said all that...
If you were going to do it, I'd take a hard look at the Milan and it's Ford twin, or the new Taurus line - they have V6 AWD packages, I think. Start there, add a big turbo system, beef up the transaxles, have a blast. You might make the drivetrain fit in an S197 body, and with enough dough maybe the 4.6 would mate up. Maybe.:scratchchin