You know I'm inclined to agree with Mike on the locker... you'll be able to get that truck pretty far with some good line selection and power braking. If you really do add a winch there's your savior if you get too far. And you want to be all the way open on snowy roads, IMO, especially with a light back end.
Have you considered a more tube-style bumper a la Allpro that gives you almost the same protection at half the weight? I don't know if anyone produces one for a Tundra but you certainly know people who can bend & weld... something like this http://www.allprooffroad.com/9504tac...04frontbumpers