Best Fuel Pump Advice for Newb...

All the pump needs to do is fill the bowls. The bowls are atmospheric pressure. Pressure in the line only needs to be enough to refill the bowl as the float drops and the valve opens. And not too much or the pressure will push the inlet valve open. Mechanical pump is all that's needed for what you're doing and you'll save yourself a headache with an electrical system design not really appropriate for running loads on the battery.