Once again I'm jumping a bit ahead of myself on mods. I want to try and get some locking hubs in the future. My question is what brand should I go with? I was thinking about the Aisin ones because that's what comes stock if you have lockers (Please correct me if I'm wrong, I thought I remembered reading that Aisin are pretty much the OEM Lockers for a Toyota 4x4)
Also where can I purchase them? I've checked the local junkyards and all of them are either gone, or broken.
I'm wanting to install these myself, how difficult is it to install these? I have the auto hubs (I think they're the ADD ones, where I can just shift into 4WD from in the truck, and go) does that make it more difficult to install them?
One more question, what should I get, should I get front or rear lockers? I'll probably eventually do both (if that's suggested

) but what would be better for me to do right now?
Thanks for any help
-Braden