This might be a silly question, but really it's a matter of practicality.
What's the smallest vehicle by PHYSICAL SIZE that can tow a two-horse trailer with two horses in it?
I really want an F-250, but it literally will not fit in the parking spaces at my apartment complex (a visitor had one parked here the other day, and it was pretty much exactly the width of the parking spots, leaving no room to open the doors if someone was parked next to them). If I can't find something more narrow, I just have to go without a trailer for at least another year until my lease is up, and then see if I can move somewhere with better parking.
Which is fine, if less than ideal. But if there's a smaller alternative that can safely and comfortably tow, I'd love to hear about it.
(I can park the trailer at the barn, so that's not an issue. Just the truck.)