Ditto, a lot from Amazon (price and convenience). The other stuff came from many different online RV and Marine suppliers, depending on price and availability. No special favorites though. I even used local companies a few times. Once to order a fresh water tank that arrived with fittings in all the wrong places. They took it back with full refund, no problem. Then I ordered another from a local plastics supplier, and they included fittings custom-installed where I specified. There are benefits to buying local, but price isn't usually one of them. Returns are generally a bigger (expensive) hassle with online orders. I'll have a few leftover bits that were too much hassle to return.