[twindman]

I have a short bed and use a slider, but I don't think you need one with a long bed. And the newer Montanas (5-7 years?) have a curved front and will almost go 90 degrees before hitting the truck.
As to power, I don't know about Fords, but I assume you have a gasser??? If so, I would definitely say no to a midsize or larger Montana. I had a 2004 Silverado duramax and pulled a smaller Montana that weighed around 12000 lb I think and it worked pretty well. And I do most of my traveling in tall mountains, etc.