I am running a similar size as you for 120k now on my JKU (first Copper STTs, and now Dick Cepek MTs), and am using the stock fire carrier with new rubber stops that shall stop the wobbling between the spare and the tailgate (however you call those things).
After 100k with the E-rated tire on the back, the tailgate hinges wore out and it started to rattle. I bought the MoRyde heavy duty tailgate hinges with the tailgate reinforcement and now everything is super solid. I still use the stock carrier, which easily carries the weight, but the weight is now on the reinforcement/hinges and not on the tailgate itself. Which means that the danger of breaking welds inside the tailgate, as I read some of other Jeeps showed, is now gone.
So nothing to worry about for now, but something you might want to keep in mind. The installation was super easy with regular hand tools and a can of spray paint - the body is not painted underneath the stock hinges...