BD, the problem with using the OEM fuel pick-up is, it's too small in diameter. A pump has to suck pretty hard to flow enough fuel. It might be OK, depending on your engine's fuel requirements but the life of your pump won't be as long as it would be with a properly sized fuel pick-up. In early Pantera's, the fuel pick-up and sending unit are separate. If you installed a late Pantera sending unit (with integral fuel pick-up), you could then tee the two pick-ups together. Your next problem will be coming up with a fuel return line. Pantera Performance in Colorado puts the return line in the fuel filler neck. For an electric pump, there are tons of choices. I use a Bosch "044" pump. It's cheap, quiet and super reliable. There are lots of cool billet mounting brackets available for them too.
There may be better ways to solve your fuel pump situation, such as an in-tank pump like Bosswrench has, but I'm not sure if you could do it without removing the tank.