I’ve shipped two horses from MA to VA - I went with box stalls since a) they are both big boys (17 hh+) and b) I wanted to give them a chance to put their heads down during the ride. Both horses are prone to be nervous/stall walkers when left inside for too long, but both walked off the truck fresh as daisies. No stocking up, fever, etc either. Worth every penny!
+1 for box stall. I sent my mare tied on a trip that was only supposed to be 8 hours… with weather and some other unexepected issues, the trip was almost 3x that long. It took her literally months to recover, and she honestly was not the same horse after. She was a little bit older, but went from a sassy high stepping mare to dragging toes and feeling stiff and icky. Vet thinks the trip put too much stress on her SI because the the position she was in, and the bad footing in the trailer.