Eric,
(I am sure you've heard all this....)As with any locker in the front axle, you will have a bit of a bear steering under power in four wheel drive. Another draw-back to having a full locker in the front will be a tendancy for the vehicle to drift downhill when traversing a side slope, and the vehicle will have a penchant for driving perfectly straight in mud no matter how far you crank the wheel. But if you have hubs, you can always turn one out till the gnarlies, or shift into two wheel.
That being said, just about any locker will work up front. Due to certain longevity issues(which some have had and others have not... I have), I would recommend going with full carrier locker as opposed to the currently offered case inserts (ie EZ, LockRight, etc.). My personal favorite is the detroit but if money is no concern, go for the OX Locker or Tera's T-Locker, both of which are absolutely bullet proof and can be switched at will between open and full lock, they are incredible (you'll spend about a thousand bucks for either of them). If you watch eBay, and this site, you can pick up a Detroit very, very reasonably... I just snagged a brand new one for a HP 44 I'm building for 400 bucks... which is only about a hundred bucks more than buying a LockRight. Believe me, that's a hundred bucks well spent.
Depending on the type of axle you are working on here, there are a lot of options. The fact that yours is a daily driver may be even more reason to go with something a little more substantial that the LockRight or EZ Locker, because if your front axle turns when in two wheel or you are full time, then the type of activity that is most harmful to those lockers is happening all the time..... engaging and disengaging all the time. If your front shafts are dormant until you engage hubs and are off-road, then you are probably fine with the two you first mentioned.... I prefer the LockRight in that case.
I am sure I have just confused the issue for you... but in this case it truly is a case where a few more dollars will go a long way.
-JJ
