Originally Posted by chipcom

Without knowing what/when/route you are riding, it's hard to say with any authority. You obviously don't want to be lugging a set of studded tires across the country, so I would advise a wide, inverted tread tire...Conti Top Contact winter version comes to mind. Fenders and decent lights are a must for touring any time of year. For wintery weather, disc brakes and internal geared hub is nice, but not required. Beware your cables and derailleurs freezing up. Make sure you have the appropriate dress for colder weather...a wool sweater, cap, winter-weight socks and long johns, a poly base tees, a good wind shell, roomy shoes to accommodate the thicker socks, good full finger gloves, etc.

You might want to check out the winter cycling forum, as well as the touring forum for more information.