Unless you absolutly must have a locker I would suggest Truetrac Front and Rear. You already Have ESP. The truetrac wouldnt give you any of the noises and handling issues that a locker would. Although it is untested as far as I know, Its my opinion that the ESP truetrac combo would be NEARLY as good as a locker in most situations. But nothing beats a locker for traction when it comes down to the nitty gritty.