If it were me... And it will be eventually....

Stock 5.7l block
Stock 6.1l crank
Late 5.7, 6.1, or 6.4 heads

Turbo so you can set boost with a flip of the switch.

Low boost 700hp mode for pump gas
High boost 1000hp mode for race gas

Be prepared for all of the parts of takes to support a 1000hp motor too!

Trans, fuel system, good shocks, efi, etc...