Plumb Old Airstream as Restaurant..Help!

I am 90% finished with my project, a 66 Airstream converted into an espresso shop, etc. I have plumbed that which needs to get water and is supplied through an external attachment to which a hose will be fixed. I would like to install a water tank (the original) and be able to pump water myself if necessary. What things do I have to understand in order to do this??

Should the hose inlet channel water through the tank? or should it be separate? Is there some kind of regulator needed on the tanks to control pressure? What kind of pump should I buy? What other parts? And what questions haven't I addressed cause I'm just too uninformed?
Thanks in advance
Lance

water

IF you are going to use a tank, the main feed should go into the tank and then you use the water from it to keep the water in the tank from becoming stagnant and polluted. There are many kinds of pumps, but the most useful is an RV pump that starts when you open a faucet, and stops when you close it.

All I can say is is that I hope everything you are doing is in conjunction with the Board of Health that is in the County you will be selling in....it seems that they all have slightly different requirements for food vending...

Thank you...so the feed is a potable water hose into a tank that has another outlet that should be connected to the plumbing system (including the on-demand hot water system), yes? The RV pump that you refer to should be there (right after the tank)? I just realized that the espresso machine has its own external pump to pull water to it. How does this notion figure into the system?
TIA,
Lance

Thanks, the health dept in this county uses the state regs which are very general and mostly rudimentary, surprisingly enough.
Lance