[DFBonnett]

I doubt you'll find one that could produce the requisite fuel pressure of about 45 PSI. Then you'd have to fabricate some sort of pick-up tube for the tank. A pump that will produce 45 PSI is going to produce a lot of heat. How would you cool it? The gas in the tank sloshing over the regular pump dissipates that heat.
At the end of the day, I think your best bet is to bite the bullet and buy OEM or at least a quality aftermarket item, not low end junk.
Your call.
FWIW
YMMV