My enclosed trailer is only 22' long and space up front is tight so I didn't want to permanently mount a winch up front.
I had the fab guy here at work weld a standard 2" trailer hitch receiver tube(bought it at Tractor Supply) on to a 8"x8" steel plate. I had the tube built up off the plate about 3". I mounted the plate in the front of my trailer with a similar 8"x8" plate bolted under the center frame channel, under the trailer.
Then I mounted my winch on a receiver plate that slides into the receiver tube. I can remove my winch for storage and slide it in the receiver tube when I need it. Sorry no pictures available of the winch right now, the trailer is buried under snow.