Pirelli Sottozero is one good brand and model but be prepared to pay up some good coin. While you will be paying more, it will be one of the best winter driving experiences you'll have. What's your budget like?
I was thinking about just getting regular snow tires and putting a can of fix-a-flat in the car. I always buy a second set of wheels for my vehicles so I can mount the snow tires myself. Our tire stores get 8 hour waits when snow comes. Plus, I take them off in between major weather incidents to save on wear. However, I am striking out finding reasonably priced used Mercedes wheels on Craigslist.