904 or 727 build recomendations going behind a twin turbo 318

hi all,

im building a drag car, its not a mopar but running a twin turbo 318, aiming for 500rwhp, so i need a auto that will cope
so wanted manual valve body, either reverse or forward.
im a manual gearbox man myself but i know i should go auto,

so what do i need to build a tuffish auto

cheers
Ash