I think it depends on the type of 4WDing you do. You also need to determine what style of traction aid you ultimately want. I wouldn't put an auto locker in the front because sometimes I do high speed, slippery mud driving and certainly don't want my steering hampered.
If your rear LSD actually works and you can only afford one traction aid and you drive more on road than off then a manual locking diff like ARB, Ox or Pro Locker in the front would be your best move. If you ever decide to replace your rear LSD (and lets face it, it's not a Patrol or Subaru LSD so it won't work for long) you can either duplicate the one you have or choose something completely different.
If your rear diff is open, I would put the first traction aid there. You will get more use out of it. Still, people driving terrain that I am not familiar with might disagree.
I like to run a Trutrac in the front (which is a geared LSD, not a difflock) and a auto locker in the rear. If I did mostly highway driving like my hotrodded silver 79 series turbo I would run twin Trutracs. Sadly, the Trutrac is not available for the rear diff.
I hope that helps the decision making process.