As one of the few former Excursion owners around here, let me just make a couple comments about those since you are looking. They are awesome towing machines...when set up correctly. I think you said you are looking for a 4wd tow vehicle. That means front leafs. The stock springs are too soft for heavy towing and wear out surprisingly quickly. you will also need a thick anti-sway bar, front and rear. Most Ex's need a steering box after 100K or so. And ball joints, but then what 3/4 Ford does not need ball joints done at that point...
If you do all that you will have a very capable towing machine. And the v10 is the engine of choice if you are allergic to diesel. They get poor mpg, but actually better than the 5.4 which can barely pull the truck around much less a trailer. most Ex owners report empty v10 mpg around 16. compared to 18 for a Expy with the 5.4, really not that big a difference.
I can promise you that the Ex will pull your Salem much, much better than an Expy.
2013 Coachmen Freedom Express 320BHDS pulled by a 2005 F250 King Ranch CC
A rainy day camping is better than a sunny day at work.