Advice needed with wheel size and gear ratios.

Yeah, i guess i knew how your answers would go. Guess i was looking to be surprised by the 6sp. transmission as i've noticed as the # of gears on these newer trucks increase the 3.92's and 4.10's are disappearing. Looks like i'll go no bigger than 33's, my trailer is far from the trucks towing limits so i'm thinking some towing loss is doable.

Clarification - When not towing, bigger wheels achieves better hwy milage, less torque ?