How many GAS coaches out there with "50 amp service"?

Agree with others. I have not seen any late model class A gas coaches that did not have 50A system. All had at least two batteries, also, generally two GC2 size 6V golf cart type batteries for the house. Generally, a well designed motor home will have two air conditioners if it is more than 30' as it takes additional cooling to handle the increased space. Shorter coaches with one AC would probably get along reasonably well on 30A service.