the pickup in the tank should be fairly low, so that shouldn't be an issue I would think.

Surely if you are running a bay mounted pump to run the lower pressure required by the carbs, can't you just run 2 lines down to the pump and hook them up to the pickup and return, pop an inline filter on the pickup line before the pump and you should be good to go.

Stupid question, but I assume you have the pump around the right way and powered around the right way too?