I'll likely also upgrade my front diff with an ARB locker when I regear.
I generally agree with that kind of philosophy. However, if the OP knows he will be traveling moderately technical trails which are also remote, then selectable lockers are a very good to have, if not outright essential. Lockers are one of those mods that will go unused for the most part, but when you need them, they need to work well and are often the difference between getting stuck somewhere and crawling your way out. I've only had to use my rear locker a handful of times, but in almost all of those instances, I'm 99% sure that I would've gotten stuck if I did not have a locker. I equate them to fire extinguishers or life boats; you might wonder why you spend so much money on them for the limited use they seem to get, but when s%*t hits the fan, you'll be glad you've got them.Before making a decision either way, make sure you really need one. If you are doing 5,6 trails (on a 10 scale) then you may not even need either one. Good driving skills can do a lot towards getting a fellow through some rough stuff. If you do find that you need something extra to get you through, then go with a rear first and again see how you do.
Airing down and skillful choice in choosing a line makes a big difference. My philosophy has always been not to add anything until I have a proven need. Of course I would not have had to fix my door if I had put on sliders before getting into rough stuff. But usually the wait and see method works well. I have followed some folks with open dif's, 31 inch tires and no lift and been very impressed with where they go. Good luck on your choice.
As the clutches, in most limited slip diffs, wear their ability to limit slip goes away, giving them performance ranging from anemic (new) to open. Use of excessive friction modifier additive in the differential grease also can reduce performance. Use of gear lube without the friction modifier, temporarily, greatly improves performance until the spider gears loose their teeth leaving people that do this faced with towing and replacement of both the diff and ring and pinion (damaged by spider gear teeth) along with the installation bill. Usually the performance of worn limited slip diffs can be brought back by replacing the clutches; though this can be PITA. Some improvement, over new stock, can be had by fitting an extra clutch into the packs (often requires lapping a used clutch plate until it can fit).I know what you're saying. I've had LSD's on multiple vehicles and the NEVER, NEVER, worked worth a flip.