I wouldn't run a 6" + lift on 33's, but that is just me.
You can upgrade axle shafts or find yourself a matched 44 (I am pretty sure your Sahara is 30/35). If you wheel your Jeep at all, which is amazing you haven't broken it yet, then I would concentrate on your axles anyway, seems like that is the weak spot. Maybe regear while you're in there for a little more pep. If you're on a budget start with shafts.