When I was shopping, a day after the new GMC hit the lots (not literally, but close), they wanted $4k more for the GMC than the RAM. It was a '14 RAM vs a '15 GMC. Don't be scared to look for a new GMC if you are going to buy a new RAM. I would have paid $2k more for the GMC, but they were hung up on the $4k. Now that the stink has worn off the GMC, I bet you can get them much closer together, thus getting exactly what you want. The DEF tank on the GMC is stupidly placed, but otherwise it is a great vehicle and it was the best riding and best off the line truck I drove. The rear seats passengers did not get hvac (my 07 tundra had rear air vents...WTF GMC) and do get the joy of the front seat ventilation blowing hot (maybe stinky) air in their face...sucks to ride bitch in a GMC!
Good luck.
- Torg