Everybody has opinions and reasons to go the direction they did.
Well here is mine.
I carry a 3500 LB dry weight caribou and tow a 1500 lb trailer with a 3800 lb race truck. truck has a supertruss with 48" extention. Pulled it with a 94 F350 DRW extra cab. did the job but that IDI 7.3 turbo was a little under powered.
Now have a 1999 F550 crew cab dually with pickup bed and 7.3 powerstroke.
No comparison. Best move I ever made. Requires no suspension mods.
As for fuel cost. Just filled up at $3.31/gal. Gas was higher.
Milage for a 2 ton truck with Dana 135 rear end and 4.88 gears. 12.5 MPG all city driving and 15 MPG at 70 on hiway. That is empty.
Loaded 12 on flat and 10 to 11 depending on how many climbs it has to make. Up hill outside palm springs kills the milage but truck does it with out slowing down.
My first f350 4x4 with a 460 got 5 MPG pulling a tow hauler up that stretch at 30 MPH.
If it is in the budget my suggestion is a F450 or F550 diesel. If buying used get into the 7.3 powerstroke. They are 500,000 mile motors.
Runs comercial tires (hercules brand) that can be had for $160.00 each and you will get 75000 miles out of them.
Just my humble opinion. It is what works for me.