clutch help?

My son needs to explain why he is looking for clutch advice... We are looking into running a turbo on his 68 383 Dart. From what we have found out and been told it could hit the 800 hp range with 15 lbs of boost. So far we have not been able to find a clutch that doesnt cost as much what we give for the car. Mcleod does make a clutch that will hold 600+ hp and still streetable without having to rev the motor and slip the clutch so that it dont chatter so bad...
This was to clear things up a little...

Thanks
Rick Sr.