At your mileage rate, get a diesel 3/4 or better 1-ton. Thank me when you sell it in 5 years with 100k miles. Resale will be significantly higher and you get to enjoy all the 800+ ft-lb or torque.
If you stick with half tons, watch the payloads. If some are under 1000 pounds and others over 2000. Check the as equipped payload per the tire and loading sticker when you open the driver;s door and check them out. You'll want enough for 1000 pounds of tongue weight, 200 pounds of camping gear in the bed, and your passengers.