It's really too bad the truck designers make the box sides so high on new trucks, just plain dumb!
Our 5th, which I believe is basically the same as yours, has a front end height of 57 inches when level. The box on our TV is 53 inches high, and we have 6 inches between the box rails and the camper, which makes 59 inches, but the truck drops 2 inches with the 1600 lb (estimated) pin weight, which works out perfectly (we got lucky!).
I just measured my 2010 Dodge 1500 4x4, and it's box is already 55 inches high, so I wonder how much higher the 2500 would be, if any?
I imagine your camper will have the rubber axles, so it wouldn't be that difficult to add another tube under the existing suspension box, but just make sure it is done carefully, as the axles must be mounted precisely in line. I have a feeling that most of the complaints we hear about blowing trailer tires comes from misaligned axles.
The only other option would be to get a truck with a low gear ratio, then put shorter tires on, thus dropping your truck height. But that would probably be unattractive. I have seen it done, though. Just make sure not to order oversize tires. The 20-inch rims and tires may have a larger diameter than the 17 inch, worth checking, even if it is only an inch, as that's one inch less you would have to raise the camper.
You can pull the camper with some 'nose-up' attitude, but too much is too much.
Good luck with your new camper, I know you'll luv it!