I had a 2003 wrangler x, Aussie's F&R with 35s for 3 years, wheeled hard and never broke an axle shaft or did anything major. It all depends on how you wheel and if you like a lot of skinny pedal. I wheeled mine almost every weekend. I would say air lockers. swap in an 8.8 axle and be done.
Just A Jeep...
Way of Life!