Welcome to the JOF forum, lots of good help here!
My 26BH was about the same weight and size of what you are looking at. Pulled ok with a 4.7 liter Tundra, however was working hard going up hill.
If you are going to get a Ford look at the 5.0 Liter or if you want to take a chance on the reliability of the 3.5 Ecoboost go for it. 3.7 Liter will not be a good choice for you.
2012 Toyota Tundra 5.7 Litre DoubleCab
6 speed, 4.30 Limited Slip, Tow Package
2013 Jayco White Hawk 27DSRL
2010 Jayco JayFlight 26BH sold
Yamaha EF2000is Generators (2)
1996 Honda CB750 Nighthawk