I know I always post parts that are sometimes pricey. This is part of the reason that high quality toppers can get very costly. My custom build has almost hit a grand in parts already. I can only imagine what it would need to sell in a retail market to actually make a profit on it. At least I...
Here is an option for a waterproof hinge.
https://www.usplastic.com/catalog/item.aspx?itemid=23843
https://www.tmhardware.com/UNIGEAR-Hinge-Half-Edge-Mount.html
Here is one I found at Barret Jackson. So I guess people are starting to sell graphic packages or Mopar is selling them now.
https://www.barrett-jackson.com/Events/Event/Details/2020-JEEP-GLADIATOR-CUSTOM-PICKUP-233224
For me I can't justify the expense of replacing the bed. I feel that it is limiting functionality. I would rather spend it on a custom top that gives me a lot more options. Plus from a resale point of view not as many are going to want a configuration of a tray bed. Just my 2 cents.