I know you probably don't want to hear this.. But I'd sell the F150 and buy a van. Something like a sprinter or one of the new ram promaster vans.
Lots of race teams are doing something similar, set up the van to hold all bikes/parts, and pull a (small) travel trailer. But the nice part about it, is all bikes will be secure, and dry, and you'll have more options for trailers, as small toyhaulers are very limited in there usable space when the "Garage" is full. Typically you'll have to move most of the bikes out to sleep in the trailer. Far from ideal.
Motorhome/cargo trailer, might work ok, but then you won't have a vehicle to drive to the trailhead every day. Setting up the RV, then taking it down everyday after a bike ride would get old fast.
http://singletrackworld.com/forum/topic/5-bikes-across-van-with-underfloor-storage