I have been looking into this - yes the Rubicon has a front E locker, but it is a Dana 44 (F&R)- The ones I have found for the Dana 30 are: OX, ARB for a positive on/off lock (Eaton does not yet make an E locker for the Dana 30) and if you do a google search, there are a number of part time or positraction types out there - general advice from what I hear is do NOT put a part time in the front end if this is what you are looking at.

Richard - 08 JK, 2.5" OME lift, nitrocharged shocks, Rugged Ridge front bumper with M8000 winch, JKS QDs - Olympic 221 rock sliders and rear rock crawler bumper, upper adj control arms f/r, JKS adj track bars f/r