I have a 2000 Expedition with the 5.4 Tow Package, with the Factory Bags...
It tows my Wrangler great... As said its not a diesel
Daily I get 14-18 but usually around the 15-16 range.
Towing i am around 10-12mpg
I think a 5.4 Expedtion would be better because thats less vehicle the motor is pushing, and my 2000 has a solid rear axle.
Get the one with the 3rd row, and captains chairs, its a nice package
I have 154K on mine, with no issues, I have replaced a couple of coil packs and a heater core. that is it, since new.