What options do I have for locking the front of my 96 Tracker? 

There's the standard mechanical locker, welded, but I prefer the selectable locker by ARB. If you have the coin they are the most effective and non intrusive when not being used. Cost a pretty penny though. I'm sure there are other choices available too. One thing for certain though: If your going to put a locker in an aluminum front housing you need to brace and strap that sucker down.

I agree with Bentparts.  Also you can get a spool, which makes it solid same as welding it.  Turning with a solid locker up front is harder, and the harder the ground the harder it is to turn, unless you either unlock one wheel or go to 2wd (and most of us do not have 2 low ability). 
In reality I do not use my front ARB that much, but when I do it is amazing.  I do use it more than a my winch, which encourages me to go places I wouldn't go without it.

Thanks or the replies. I guess I will save up the coin and get a rear ARB.

Thanks or the replies. I guess I will save up the coin and get a rear ARB.

They work great there also.  I never could get my lunch box locker to work correctly, on slow sharp turns when it unloaded the tracker would jump 12-18 inches.  Then I got an ARB for fathers day for the rear, now I have them on both ends. 
Pay attention with routing your airline, it will melt easily when hot.  I had my rear air line spot tied to my Auto Trans, and when a cooling line crimped it melted the air line and then no locker.  Also get at least one of the push together splices for the 5mm air line when you get one.  They are hard to find anywhere when you need one (LROR has them).

I got my air line repair kit when I got my lockers, Haven't needed it yet but it's good insurance