Your talking lots of boost to hit that number. I would want iron block. You don't need a stroker or a big bore to hit that kind of rwhp. John Urist SSO driver and owner of Hellion Power Systems just did a kit on a stock 03 cobra and I believe laid down 847rwhp. This was a very stock motor if memory serves me correct. Urist said that he could hit 1000rwhp with nothing more than some 116 octane fuel.
The motor would basically need to consist of good components,and be built for boost, low compression, so your not talking a ton of money on the motor, the turbo and fuel system will be the money.
Adam