For a moment I thought that was your front axle and was wondering how freeing yourself from the first photo would matter if you only had 3 wheels.I run a rear winch on my 80 (it actually just saved my butt on a solo camping/wheeling trip this past weekend). I ran 2/0 from a single front battery, but definitely overkill. Put something like this right off the battery connection so you don't have a live, large gauge wire running under the truck during normal circumstances.
Amazon product ASIN B00445KFZ2
Rear winch in action. I was 2+ hours from help too. Great if you do a lot of solo trips.
Then I realized after zooming in you buried your spare as a winching point. Very nice