Hi everyone and thankyou for taking the time to look at my thread

I'll be soon purchasing an RS Turbo with the view to building my own engine. But before a draw up a shopping list, im after some info on what the following items can cope with power wise and whether the CVH engine responds well to certain Modifications
Right then, a few questions:
1. What BHP will the standard crank cope with safely?
2. What options are there on the Clutch front to handle decent power levels
3. Is a big valve head, gas flowed worth while?
Cheers for the advice in advance