Gar, welcome!
With that truck, you can handle pretty much whatever camper you want and still tow a little boat. Campers under 9' long you won't need a hitch extension, as you're aware of. If you do end up going longer, a simple extension or a more costly extension (unless you fab your own) will be requisite.
As far as used campers go, IMO, the brand is not as important as the condition of the camper and the main thing to look out for with any RV is leaks/water damage.
I've never found the height to be an issue, save for the one time I cleaned the AC unit off the top of the camper, lol! But someone was giving me directions saying it was clear, haha...
Been X country, to AK and mostly all boondocking areas with a pretty tall rig. 12'-3" tall before the AC departed ways. Not an issue. Most any place you're going to take a top heavy dually has already been traverse by other RVs, logging trucks, etc. just have to have some spacial awareness.
Good luck in your search and nice job on the truck!