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