i have wondered/worried about cog, i had ATC put our 30 gallon (ish) tank right under the window up against the back wall. Both propane tanks(one on either side) are beside that. Balanced out both cabinets, five feet long per side. Most of the weight is low and forward.
Camper is up there though, with top down, i am about 8'6". We use the tork lift glow steps, i think we have 5 or 6 with the levelers, they are taken off when we are moving.
When we put this together i knew there would be trade offs, not as nimble as a taco but much much roomier. i know this isn't a crawler but it;s size hasn't stopped me much yet. Won't be doing black bear pass, most likely too long. There was a trail or two that i was just two wide. Even the jeeps had to stop, but man the wife loves having a nice bed, heater, place to hang out on nasty days and a big kitchen area.
Hard to say, i would like to do a cab and chasis, and try to get the bed height down. My idea is to start the walls 6 inches lower and have them go up 6 inches higher. Then i could use it pretty comfortably with the top down.
the wife says i have and addiction.