Most winch plates for trailer have the mount for the fairlead attached to them.
I Saw a trailer MFG that just put a steel plate in the deck with holes and called that a winch mount. Not sure what your trailer looks like.
Just wanted to thank all the smart people that have posted info on here. With all this good information my dad and I were able to put in a new 100 AMP breaker box and rewire my whole garage. Now its more suitable to my needs, instead of the 40 year old wiring that was in there.