ARB and eaton 4-pin e-lockers are both good choices. I run ARBs myself, and last April, when I broke one on the trail, ARB sent me a brand new one right away. I will be an ARB customer for life. I have a couple of buddies that run the eaton 4pin e-locker, one of whom has broken one. He didnt' have much luck w/ the warranty however.

 

Just installed a new front G2 Core 44 with 5.13 gears and an ARB locker activated by my new SPOD on an 09 Rubicon and love it. Didn't have the $$ to change the rear so just did the gears on the rear. But now I can lock either or even if I want just the front locked up.