IMO, a winch is a must have. You say the type of riding you do shouldnt require you to need one BUT, there's always the chance that you get an invite to go someplace that could hold some nasty terrain. You'll need it for the plow anyways so I would just work out a deal with the dealer and have them put one on.
Like someone said above, get yourself a small portable air pump and a tire repair kit, that's another item I wouldn't leave home without.
