The main thing that got my attention was that you said you were planning to travel around the U.S. Some people buy a travel trailer, never tow in the mountains and seldom go more than a few hundred miles from home. For them, being "maxed out" might be ok. But if you really want to see the U.S. you are obviously going to be covering some serious miles and many of them will be in the mountains.
I tow a 29' TT that weighs in at almost 7000 lbs loaded and my combined total weight (truck and trailer) is close to 14,000 lbs. I'm doing it with a 3/4 ton diesel and wouldn't do it any other way. But that's just me. Sure I'd tow it 100 miles on flat terrain with a 1/2 ton, but for the trips we take, no way.
Personally, I think DutchmenSport's advice is spot on.