What would you want power wise? As for the 700r4. Many place do them well. It would be a combination of power and weight for that trans, not just power.

As for who to get the motor from, VortecPro out of Colorado. Even his milder 467 would do what you want. There in the $6200 range. That is a 467 with 570Hp hyd cam 9.6 to one compression. Get him to tube the Snioer EFI and its smooth sailing.