1st Gen, 4cyl aftermarket Diff lockers?

So I love my 2.7L 2003 Prerunner, I just have the sole misfortune of running an open diff in the rear. I would really like a selectable locker if possible. I've done some shopping, and I got 3 options from the shops in the area.
1. ARB Air Locker. More than 2K installed, compressor is extra, too high end for me.
2. Eaton auto locker. Total locker, but will eat up tires on slower turns from a stop, and not selectable.
3. Eaton LSD. Best of the 3 for me, not a total locker, but I'm mostly on-road anyway. Not selectable though, of course.

So what I'm getting at is this. Does anyone know of any other diff upgrades, preferably selectable, for a 1st gen 4cylinder?

 

Snow and foul weather in the hills. I know a LSD would seem like an obvious choice, but i'm wondering about selectable types.
...and not yet. I'm checking the links now. Thanks for those.

 

Thanks for the links, unfortunitly no matches for my application it looks like. And no hits it looks like for selectable lockers anywhere, except the top dollar ARB. I'm starting to lean towards settling for the Eaton LSD. Selectable anything is kind of just lots of extra points for me.