Don't spool the front. Unlike rear tires, front tires take vastly different paths around corners and curves. There's a lot to be said for leaving the front open, actually.
The thing to understand is that with an open axle, if a tire isn't spinning, it's delivering 50% of the torque. That's a simple equation--50% or zero. If you are maneuvering through an obstacle, a locker rear will make the front much more effective because the rear locker will greatly reduce the chances that one front tire will spin: both rears have to spin before one front will spin instead of just one. Having the front open gives you much better slow-speed control, especially on slide-slopes where if both fronts are locked, you go sideways down.
If I could put anything in the front, it might be a Torsen. I might consider a selectable, but I don't like the idea of control wires or air hoses coming out. I churn through a lot of blackberry brambles and downed limbs. I have an automatic locker, but it definately sees the side-slip issues. I think it adds maybe 10% under most circumstances, and some of that is negated by its tendancy to slip sideways. Going full blast through mud, yeah, you want both locked. A real rock crawler, a selectable I would think. A mild offroader, probably open in the front and a rear locker. There is a big difference in open and auto-locked on snow. The auto locker is unpredictable because every slight correction in the steering unlocks and relocks an axle and the steering wheel is constantly jerking and feeling disconnected from the truck. It's workable, but you really have to pay attention. Front spooled on a snowy road? How do you steer at all as neither tire will ever be going the same speed so one will always be spinning, and they will take turns. I see that as death on a stick.