This is part of the email that I got back from the tankless contact.....
Obviously, for a "mobile" unit you'd want to be sure there are no fragile components (which these have none) and fuel storage safety.
Since it opeates on LP gas, the source of gas is containerized in UL listed - tanks that are safe for travel trailers.One note: This unit does not have a standing pilot light, so there is only CO2 when the unit is operating
I think that this is the tank that we are going to go with and see how it goes.
Sorry should really have said "tankless"!!!