I do not currently have my TC on a flat bed, but that was my next change to my setup. I have always thought that a slide in on a fleetside bed was such a waste of space, without access.
I am planning on changing my RAM 3500 DRW to a flatbed, with a super singe rear wheel setup. I have a 10' camper, and as I have been doing research on what I want to do, I think your 8.5' camper idea, or even a pop up camper is a good choice...especially if you want the freedom of launching a boat regularly and getting up into less traveled locations.
1987 Western Wilderness Alpine 10