For towing get the biggest truck you can....4x2 is what we found to be best option...for a lot of the afore mentioned reason...plus we got the crew cab and 8 ft bed for longest wheel base possible...IMO that increases towing ease...plus the 3/4 T allow all sorts of hitch and pin weights. as long as you are towing under 10k gas IMO is good option....2500 HD 3.73 with 6 speed that slows you down....we hardly ever have to touch the brakes. Yes is PIA in tight parking in town, but you learn to find the spots that are not too much trouble.
We do get as much as 18 mpg with careful driving and not speeding....when towing is 10 mpg with truck loaded and trailer w/camping load....including water. Worst mileage was 9.5 with headwind and mtns....best is 12 flat with tailwind....course our tow speed is 56-58 mph.....if you plan for more than 10k
you should get a diesel....enjoy your shopping....