Hey David,
I think you willl be pretty happy with the 2500HD. I bought an 03 to replace my 1500 a couple of years ago and never had an issue. Truck pulls the car and trailer like its not even back there. If you do find anything to help out with gas mileage, pass it on down the line. Mine gets about 17mpg but mines not a 4x4 either. Don't really need it in Ga. Good luck, you should have no problems....
Chris