have you worked through all of Cruiser's renic tips yet? I do believe one of them is for adding a ground near the fuel pump.
could also be a bad pump, or a failing harness inside the tank.
batteries tend to be cheap. I bought a 3 pack for like 10 bucks on ebay. memory is also cheap if you have a card slot. processing power is the real kicker with my old phone. even if I updated the OS I'm stuck with the old, arthritic chip.
all depends on what you put in the bed, but an LED light string on either wide can work better than a single cab light. you could always do both later on.