The Texan wrote:
Tell the dealer to find you a 2013 Chev/GMC 1500 with the 6.2L engine, 3.73 rear and the NHT tow package. That will give you 2000# of payload, towing capacity of 10,700# and a very comfortable truck that will work for you. We have one, tow 10,000# out here in the west and are very happy with our choice. We have 4 other trucks both ¾t and 1t on the ranch to use, but am completely satisfied with our Chevrolet 1500.
This sounds like a good choice, but may be hard to find. If you can't, I'd go for a 3/4 with the 6.0 if you want to stay with Chevy. I towed in the mountains of Colorado with a 5.3 Chevy last year. Note that I no longer have that truck, even though it has less than 50K miles and was a fine commuter.