Gears before locker. Even if you have the front locker first, your gearing is so off that you'll end up burning you clutch out and breaking axles from going to fast.
The lockers and ring & pinion gears (5.62's) were put in at the same time and that was okay. But still, when it came to tougher climbs, the ole clutch got one hell of a workout. Now that I have installed the 4.24 t-case gears, what a difference. I loved it when I was climbing up hills and rock outcrops that the jeeps were having one hell of a time climbing...and I noo problem even with my A/C on

It just crawls under minimal power. So I would recommend the gears. Good luck!