Sink on Off Set Trailer - would like input

I helped a friend add one to a 500 gallon tank, but don't have any pictures for you. I can tell you he used two stainless steel tanks to hold the water. One was cut and welded into the upper back side of the smoker where it would get heated up. The other was welded to standoffs so it would not get heated. Both were then plumbed into the sink with copper lines. The sink drains into a aluminum fuel tank located under the smoker that has a drain hose on a ball valve. It hold 2 1/2 times the fresh water. Also don't forget to take out the water restrictors in the faucet or you will not have any water pressure.

the idea I had was setting a trl up for city water and using a camping propane tankless water heater. then setting up a plastic pallet with two 35 gallon tanks in the pickup with a 12 volt pump to supply water where none is available.