Trying to decide which way to go on fifth wheel hitch

Not a fan of the Andersen aluminum, which is probably what your neighbor had ,I'm guessing . But thats not the subject here, its the steel rail mount Andersen.

As far rocks , had to be ,that or sand or dirt. My previous truck had the bedrails, and don't remember hauling rocks, but I did haul some mulch ,and top soil. no big deal ,but I did cover the bed with a heavy tarp . It was not earth ending dealing with the bedrails .