I'm about to rebuild the knuckles and replace the hubs. I figure while I've got the front in the air I might as well install a locker. I've got some cash saved from VA disability and can afford the front locker now. A month or two down the road I'll do the rear. I'm "frugal." I'm looking at ARB and Eaton ELocker. I'm in NM and virtually all my wheeling is in sand and rock. I have to drive a considerable distance to get to where I like to wheel so I need selectable. Pros and cons of air vs. electric? I want onboard air anyway so that's not a concern if I go ARB.