I've made my decision to go 120 only, and I ain't changing my mind.
My air conditioning unit is going to be sitting at the front on the cabin, extending onto the tongue, and that's where I also want to put my 120 box.
Because of the thicker gauge of that air conditioning's wire, and the ultimate heat buildup, I was thinking of not hardwiring that into my system, but rather, just running that line to the camping site's outlet separately.
Most sites have two receptacles anyway, right? This just seems safer and easier to me. One for the air, and the other to handle all of the other 120 load.
Now you can all tell me why I'm a total idiot for thinking about doing it like this.