I can get you the TrueTrac, Auburns, Ford's TracLoc, Detroits.
Any differential parts you need, ill take care of you man.
I have a lot of guys on here interested in True Tracs, id be interested to see how an auburn would work. Remember with a selectable locker whether electronic or air, you need to drill a hole in your housing. and Electronic lockers are very heavy compared to air.