Several important items, room to stretch and relax, BATHROOM! and discuss this with your wife. I don't think the laydown flat camper comes with bedpans.
Another idea is, just rent a small motor home. You can stand up, you can potty while moving up the highway and make sure it has a generator.
I have friends who've made this trip, after the first time they learned to take extra tires, some took several extras and sold them to locals when they got there.
My Dad's older brother helped build this highway. I guess my bro got Uncles photo album as I have not seen it in years. When being built it was pure virgin wilderness in front of them, Unc took tons of pictures. The two I most remember is one of him snapping a photo of a bear up a tree. Another is of him snapping a photo of a bear on the ground while Unc is up a tree waiting for help.
The comfort a small rental will provide will make the trip memorable. It may not be the bears that bug you, ever heard of "no see ums"? Bug spray.
I've camped all ways, tent, no tent, pop up, small RV and my 30' RV. Brother I can tell you having an RV bigger than a motel suite cannot be beat.
Also read up on laws, get your passport and guns are tricky, must be sealed and stay that way. I'd get bear spray or teach your wife Louisville Slugger kung foo.