For general beach driving, I found a stock standard Sporty to be more than ample (I'd get manual hubs though..).

For tracks with big holes, my front TF locker pulls through all I've encountered so far - maybe easier to obtain the TF front locker compared to the Eaton?
I'd go for a locker over an LSD any day, I don't find my rear factory LSD does much..

Just my 10 cents <img src="/forums/images/graemlins/notooth.gif" alt="" />

Long a$$ 2000 Sporty, auto, 5.38 gears, TF front locker, 4"+ front lift (Kings +40 springs, 50mm spacers, 1.5" diff drop), TJ 104 rears 3" + 50mm coil spacers, 1.5" body lift, 31/10.5r15's on 15x8 Kings (ET-13), WARN manuals, Smart Bar, spotties