True it'd be nice to have a winch for self recovery.... but as long as you don't wheel alone, you'll have someone to give you a tug. I've known people with winches who have never used them because its always quick and simple to hook up that recovery strap and give a quick pull.

The locker and OBA on the other hand will be used on every trail ride. Carry around a plug kit and the OBA will also take care of a flat tire on the side of the road.

And since you said "first", thereby indicating that the other mod will be done second.... I look at it as what is more useful for the majority of the time. The added capabilities of a winch are mitigated by not wheeling alone, whereas the added capabilities of the locker particularly can not be simulated and there's plenty of "daily driving" instances where OBA will come in handy. $.02