I am planning on mounting my freshwater tank inside the bus under a bench or couch, or wherever seems convenient with my final layout. The wastewater tank(s) are going under the bus to avoid drainage problems, plus it is easier to mount the toilet directly over the blackwater tank and let gravity do its thing. I have seen installs using angle iron and threaded rods. I can't remember whose install it was, but hopefully someone remembers and can point us in the right direction.