Do I really need a 12k winch?
Isn't that overkill?
General rule of thumb is 1.5 times the weight of your rig.
https://www.warn.com/blog/2011/01/20/how_to_choose_the_right_winch.shtml
Curb (unloaded, dry) weight of a 1999 Suburban is between 5 and 6K. A fully loaded expedition rig can weight a lot more. That means your minimum size winch should be 9K, but larger would be better.
If your vehicle is stuck in some mud, that mud can have a very powerful suction that keeps your rig stuck, and a winch that is too small won't be able to pull you out.
Casey