BigIron, here’s the link to the company’s website:
www.truckcoversusa.com
I have a 2020 1500 with ramboxes, barn doors, and the black rails that came with the factory cover. I exchanged emails with the folks at Truck Covers USA about their American Roll Cover product and they were very helpful in confirming that it would fit the truck. They even sent over a video of one installed on a similar truck (to show where the gap is near the tailgate). I really liked that product, but ended up getting the Diamondback instead.
What I really liked about the Roll Cover is that it’s strong (I think it can hold 400 lbs, or something like that) and that you can unlock the cover and roll into the canister WITHOUT any keys. There’s a pull-tab that you can reach when you open the tailgate. That makes it very convenient. (I wish the diamondback would also allow it to open without a key. I may have to do a little Macgyver and fix this shortcoming one day.)
Anyway, given your desire to mount a tent on top, the American Roll Cover sounds ideal.
Good luck!