Yike. I know zilch about well pumps, is this typical?

Anyway, all I can say is that whatever you can do to reduce your energy needs will reduce both your daily operating costs and also the (size) cost of a generator to back it up. And, as has already been pointed out, keep in mind the amount of fuel you're going to have to have on hand to run the thing for whatever amount of time. I agree that propane would be the way to go (unless you've got some sort of large storage container for gasoline already, like an in-ground tank, that you're fueling your vehicles from). Good luck.