I think LSDs on Libby's kinda fall into the same category as getting mine with a 6-speed manual do - few and far between. I ended up ordering from the factory to get a manual that wasn't loaded up. My dealer only found 1 within 300 miles of me, but it was totally bling-ed out. Your Trac-Loc, from the EXTENSIVE research I did through several dealer inventories while looking for a manual ******, seems to sort of fall into the same category. I came across a few with that option, but I think I saw maybe like 4 total all spreadout within a 300-mile area around where I live (southeast MA.) All of them were loaded up with all kinds of other options, too. Not saying that's a bad thing, but I couldn't afford all the extra goodies right now, so I ordered one the way I wanted it. In any event, if you're serious about it, talk to a dealer, they sometimes a better view of local inventories than you can find on Jeep.com. Just my (longwinded) $0.02 =)
P.S. The folks looking for Selec-Trac full time 4WD seem to also have run into the same issue, too.