Need some opinions on towing
I agree with the others, your estimation of that rigs weight is way low. While I would not hesitate to do local hauls of it with a Colorado, even with my Minimax I would hook it to one of the Silverado HD's for a freeway run of more than a few miles. Running that heavy and wind resistant for hours at a time can be done, but you will be sucking the life out of that truck, especially with the gasser.
'16 Z71 CC/SB Minimax. Brownstone. 5" SS boards, Quad fold tonneau, Wheel well flares. Spray in liner, swing out tool boxes, Bose & Nav. Weathertech vent shades, floor liners and mud flaps.