Since we don't have any crossbars that will work directly with your BAK tonneau cover you are going to be a bit limited.
One option is to use a set of roof crossbars like the Rhino-Rack Vortex Aero Crossbars # RRVA150B-2, with the legs # RRRLKVA, and the fit kit # DK079. From here, you could then use a kayak carrier like the Malone FoldAway-5 Kayak, Canoe, and SUP Roof Rack w/ Tie-Down # MAL38FR.
The only real issue I see with this setup is having a too much overhang from your kayaks... view full answer...
To add a wall-mount thermostat to your Advent Air RV Air Conditioner # ACM135 you'll need the Air Distribution Box w/ Wall-Mounted Thermostat # ACRG15. This is a kit is the only way to get that thermostat aside from purchasing a whole new AC system that would come kitted with the thermostat. view full answer...