When I got my 2020 I went with a Reese goose box on the fifth wheel and just a ball in the bed of my truck in the puck system works great no heavy hitches to move around.
Somewhere around $9000. Floor was solid but after removing everything including steering counsel and all the wires to gauges, I figured another $900 for all new marine plywood and I should be good for at least another 15 years. Moving the panels to the outside opened up another can of worms...
I don’t have any close up pics, but they did roll the edges as there are no sharp edges, then they put a seem down about 6 inches from top and another one up about 3 inches from the bottom to break it up so it’s not just a flat pieces of panels