I did this exact same thing about a month and a half ago in my 14 SXT. I was also unable to find a single piece of info on doing it. So, I will be glad to tell you everything I was able to find out.
1. Any 11-14 Charger or 300 seats will fit in terms of mounting to the floor. I am not sure of the Challenger since they are set up a bit differently to allow the seat to move differently for the fact that they are 2 door and need to allow access to the rear seat.
2. Here's where I had the biggest issue. When I got my seats, they were from a 11 or 12 Charger and when I went to put them in, I discovered that the main body wiring connector on my car was different from the seat's. However, all the internal motor, heater, and sensor connections inside the seat were still the same. SO as a test since I had a power cloth driver seat, I transferred the harness from my 14 seat to my 11-12 seat and everything worked perfectly. Then I had to source a 14 harness for my passenger seat because I didn't have a power passenger seat.
What I bought was from
www.moparpartsoverstock.com and consisted of:
68223323AA WIRING. Export, US, US, Canada. Jumper. Mexico. Power Seat.
68232328AA WIRING. Power Seat.
68224715AA WIRING. Driver and Passenger, Drivers Side, Export, Left, Right, US, US, Canada. Seat Back. Mexico, Passenger Side.
I put all that in my 11-12 seat, put it in the car and discovered that the main harness on my car was not providing the 12v line to power the motors!I tried to find a schematic, but that was almost impossible. I also didn't want to pay for a service manual since I'd already spent an extra $150 for the new wiring.
Thankfully, I found this:
Mopar Connection Repair Kit You'll see that pin 1 is the line that provides 12v to the motors and if you follow the circuit A942 to the fuse panel you'll see that it is the 25 amp for the power driver seat as well. So I tapped that line and ran it back to the fuse panel where I found that the seat fuse is not a fuse, but a mini circuit breaker and you can't run a fuse tap from those. So I tapped the 20 amp console power outlet fuse since it's a high amp constant 12v. It worked just fine. I didn't think of it at the time, but you could also just run a jumper from the 12v on your driver seat since they are supposed to be in the same circuit anyway. So basically if you find some seats, try and get pictures of the connectors to make sure they'll connect up, otherwise you'll have to buy more stuff. I think the "old" connector went up to 13, but I was only able to find a 13 to check. When I was searching, I found harnesses that said they were for 13 and 14 models with no pictures to verify, only low res line drawings. And I believe that the heated AND ventilated seats have an extra connector on the driver side, but I'm also not entirely sure we could get that on the 11-14. I think it started in 15.
The back seats I got were also heated but I am not even going to try to wire those, as you'd need a new console harness, rear panel, switches, and possibly new wiring ran to the fuse panel. So I've got nothing for that part.
3. The heaters worked fine, no problem whatsoever. The controls stay the same and both the bottom and back cushions heaters work. It's just an extra panel in the back and the car doesn't care.
I hope this helps you out if you still need it. And if you or anyone else has anymore questions; feel free to let me know!