I think that some clarification might be needed to get a clear answer to your question. First of all, if you are planning to travel with your coach, there are two general choices when it comes to shorepower electrical boxes 30-AMP (the industry standard before rigs with two roof air conditioners became common) or 50-AMP. Unless everything in your coach is 120-volt AC electric, it should be possible to wire to the 50-AMP standard. If your plan is to setup your coach as a semi-permanent cabin, you could look into a 100-AMP mobile home service as that would include the 100-AMP main breaker and room for your breakers totalling 80-AMPs.
Basically, on our Vintage coaches, the roof-mounted air conditioners were wired to a dedicated 20-AMP circuit as the compressor requires 20-AMP on startup. Then there would usually be two additional circuits . . . one serving the 120-volt outlets and another serving the Univolt and the 120-volt outlet for the refrigerator AC heating element. These circuits would be in a 30-AMP RV service box. When a second air conditioner or a large microwave was added the service on a modern RV often went to 50-AMP boxes to allow for the additional electrical draw from the increased number of electrical appliances.
The most important question is whether your coach is going to continue to be mobile . . . . or if it is going to become a permanent fixture on a lot.
Good luck with your investigation!
Kevin D. Allen
WBCCI (Lifetime Member)/VAC/Free Wheelers #6359
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.11 Differentials)
1978 Argosy Minuet 6.0 Metre/1975 Cadillac Eldorado Convertible (8.2 Liter V8/2.70 Final Drive)