beyond,for parts, try colaws salvage in carthage missouri, and arizona salvage in phoenix az.
often, its cheaper in the long run to just replace the whole system, with a more reliable one.
there are several companies that supply aftermarket systems. you can order them thru camping world and install them yourself. hwh, bigfoot, equalizer, and lippert all make aftermarket systems. i have no idea what pricing for the other systems are, nor would i quote a price here, but they are available on the internet.