I've had both TTs and 5th wheels and both have pros/cons that are well established - things like losing the bed with the 5th wheel but they generally tow better due to weight being over the axle. The 5th wheel tall ceilings are nice and the floor plans are generally nicer (as long as you don't mind the stairs).
Do be careful though being too cavalier about the payload for the 2500 truck. I just bought a new 5th with a 1750# dry pin weight and am sometimes over my 3000# payload. It goes something like this:
Pin once loaded = 2000
Slider hitch = 275
Myself + wife and 3 small kids = 400 (150# of my weight was taken into account before the 3000# payload)
Misc. other stuff in the truck = 200
And it all adds up to right around my 3000# payload. Some of my numbers are estimates as to how I got to the total but I have rolled through the scales several times with and w/o the 5th to arrive at pretty accurate totals. So, just be careful and if you haven't purchased a truck and are even considering a 5th wheel it's VERY wise to just get the right truck from the start - a 3500.
As for the bed clearance, there's a good chance you'll be okay. I worried about this one a lot but it turned out fine. My truck is a 2014 Ram 2500 with a very tall bed (I happened to be parked next to a new Chevy 2500 recently and looked from the back and my Ram seemed to be at least a couple inches taller). My 2016 Keystone Hideout lines up great with about 8" of clearance. 6" is considered okay - anything less is pushing it but people routinely do it.
Good luck with the search!
