I'm still on this as well, lately been thinking more about doing a 5th wheel where the slider hitch design could tuck it up to the truck better, except I don't actually have a pickup anymore. There was a $995 "handyman" special 5th wheel down at the local big RV lot's annual winter clearance that looked pretty good. It didn't get so tall as the newer ones and I thought just cutting the side walls down and tapering the roof down to the floor might be pretty easy compared to starting from scratch. It would lose the rear door and rear booth, I would lower it and take all the stuff off the roof. putting a radius on the side edges of the roof would be better but more difficult.
Then there is the hybrid style with the tip outs front and back. I thought those tip outs might actually make a good platform for a boat-tail add to an existing one of those. Heck even the front tip out looks like it might helpf fill the SUV to trailer gap.
