Take a look at the old forums at "truckcoversion.net" - there is a lot to read there, and you might as well learn from the experiences and perspectives of others. In addition, in the forum right above this one, there is a string about Warpath (Bill) building their second RV using a class 7 Freightliner. It was from 2004, and there is now a new reply in which he says had he gone with the class 8 they would probably still have that RV. A good lesson.
Research is cheap - errors you could have prevented are expensive. I suspect you will find that many, if not most, class A RVs are built for a market which is not as demanding about hard use capability; which does not travel seriously, etc. Soft suspension, ease of operation, etc, are valued more highly than I would value them, in large part because I have driven OTR and am not intimidated by a Class 8. While bigger RVs designed from scratch as such are far better than typical Class Cs, you might still find them wanting.
I am also dedicated to not having propane; to having an escape pod for social ills and pandemic illness (among my duties in my prior job were legal advisor to the Sheriff and to the Health Department); to having the ability to travel for 3-6 weeks in the summer, in addition to weekend jaunts to Glacier; room for the dogs (current range of 62-108 pounds, with the elders likely to be succeeding by a 130 pound range female of a rare Mastiff breed), and none of this silliness of falling on its face on a 6% 2 mile hill.
I am, however, the product of many years of aggression training by profession, with a foundation of it by nature. I have broken 2 exercycles because they were built for folks who are not serious about training; few are built right for that, even those used in gyms. It's a world view that is not shared by many. I make decisions, not friends.