You have mentioned fifth wheel towing in your experience. The camper you started looking at is a tow behind.
They tow differently.
When approaching max weight on a tow vehicle I much prefer a fifth wheel setup. It keeps the truck loaded properly and is easier to handle. Look into a hitch and see if there is a trailer that fits your needs.
Also if you can get your intended purchase inspected by a certified inspector:
Locate one with this link.
They could save you much heartache. They work for
you, not the dealer.