My son and I are planning to go to the Truck Nationals along with the two grandsons. I've been to other Carlisle shows many times (including over twenty years as a Corvette parts vendor at Corvettes at Carlisle) but have never been to the truck show. We are all looking forward to it. I'm sure you and your Ram 2500 will enjoy it.
Carlisle has quite a few hotels within minutes of the truck show. Any of the online hotel sites (Priceline, Trivago, etc.) should work to find the best prices. Mechanicsburg isn't too far away, either, and there are hotels there as well.