For tent camping, with my 5L, I made an "all in one" aluminum plate holder that attached to a collapsable shelf system. Essentially I had a piece of 1/8" aluminum plate about 20" x 14". To this I mounted the water heater and kitchen sink faucet system on one side and a small 12v pump on the other. I made all water lines the plug in type, so if connected to city water, then that fed the system, if not then I fed from an 8 gallon tank. In addition, I put an on/off switch and replaced the D cell batteries with those fake batteries where I installed a 12v-3.3v converter. This allowed me to just flip a switch to shift from cold water to hot. I then added in a foot switch attached to the pump by way of an 8' cord, made from an old car dimmer switch, that allowed you to turn the pump on and off while in the shower.
With the new setup, it is still a bit similar, same foot switch, same battery replacement system, but the heater now rides in a compartment in the galley then attaches to the back of the cabinets when galley is extended. Pump is now permanently installed in the camper.
Found the photos... (these were taken before I added in the switch for the pump





dave