I probably should have included this in my first post, but for the intended use of skidding logs, you're MUCH better off using the tractor's drive train to do most of the work in comparison to an electric winch. If you NEED to winch a quantity of logs up out of a ravine, you'll burn up an electric winch relatively quickly. If they must be winched instead of simply dragging them out, then you really need a PTO driven winch. If you're skidding across relatively dry ground, you're actually better off pulling with something like a 4wd 3/4 or 1 ton truck. The tractors are good for getting into places that trucks can't access, and tractors can get better traction in less than ideal ground conditions, but the tractors are also very very slow. So long as the ground is dry, I can skid more weight with my 4wd F350 than I can with a 25hp 4,000 lb tractor, and I can skid the logs at least twice as fast going down the logging lanes.
For the other uses, a 12v winch should work fine. I've had some small projects like that (elevated deer blind) where my winch has come in very handy. Lift and/or pull in one direction with the tractor and loader while lifting and pulling in another via the winch and its remote control.