6EM19TX7AB rear heated/vented switch left
6EM18TX7AB rear heated/vented switch right
68438655AA console wire harness heated/vented/usb hub/wireless charger
68433909AC rear heated/vented module
68294530AD rear seat harness heated/vented right
68294526AD rear seat harness heated/vented left
68309558AB seat back left/right heater pad
68309559AB seat cushion left/right heater pad
68267096AA seat back left/right ventilation bag
68267106AD seat back left/right ventilation blower
68267094AB seat cushion left ventilation bag
68267099AB seat cushion right ventilation bag
68267105AD seat cushion left/right ventilation blower
I'd double check it all though, but this is what I have been able to find so far. Items labeled left/right, mean you have to buy 2.
As for body wire harness, I hope it's pre-wired as that bit is expensive.
Only 3 harnesses I found with label rear heat and they arr
68443995AC Body harness Heated Second Row Seats/Driver Seat Memory/6 Speakers/ParkView Rear Back-up Camera Parksense Ft/Rr Park Assist w Stop/Remote Start System
68444058AC Body harness 19 SPKR Harman Kardon Prem. Sound/ParkView Rear Back-up Camera/Blind Spot and Cross Path Detection/Parksense Ft/Rr Park Assist w Stop/Heated Second Row Seats/Driver Seat Memory
68444054AC Body harness 19 SPKR Harman Kardon Prem. Sound/Surround View Camera System/Heated Second Row Seats/Driver Seat Memory
In my opinion, up until body harness it is not that expensive to go factory. But as soon as body harness is added, it breaks the bank. And you'd have to tear the entire interior out, if you do have to swap in a different body harness. And the wiring goes under the truck and to engine compartment. Not worth it. So unless the rear heat module can be wired to the front, with a smaller harness it just won't be worth it. If I could get my hands on the ram wiring diagram, I could figure out what would be required to make a harness for that last run.
Or another option is to use all factory parts, minus the module. Then come up with a custom module(or 3rd party module) that can be wired to the factory switches and not require the need of the vehicle knowing it has rear heat/ventilation. Not like there is a menu on the touch screen for front to control it anyhow, so why the need for he body control unit to know it has it?