KJ Oem rails are limited to only 150 Lbs. Most roof top tents are obviously heavier than that. Overland Wranglers may be better suited.
I found this 2023 review, however there is a lot to consider: https://gearjunkie.com/packs/best-backpacking-backpack
I generally camp in Provincial Parks, and like setting up camp with ground tents, making it easy to drive away and re-supply mainly for food and ice !
The coleman instant up tent can be set up in 10 minutes. Good room inside with Queen air bed !