If you have a sump that constantly cycles I'd go with a setup like Awarrior. I'd also have 2 deep cycle batteries to lessen the chance of needing the water driven pump. Because of the frequency of startups I can see the pump failing as well. That would probably have me changing out the pump as routine maintenance.
They're a little different because they had a boxed frame, which tended to collect mud and hold moisture, so it's tough to find an older one with a solid frame. The frame usually rotted out ahead of the rear wheels.