Yes, the narrow tires dig through icy crust or deep snow for traction (check out any World Rally event in Sweden or Monacco). True snow rally tires are studded beyond belief -- wouldn't be to kind to roads. In your area I'm not sure, but Four Star Motorsports should be able to help you out. It's been a while, but I think the Sprongles had something to do with this shop (used to run a championship bad-ass Audi). As for brands, Pirelli had an incredibly diverse selection of sizes, compounds, etc.