Mittens are a good idea, especially if you have circulation issues. However, I have a pair of ice climbing gloves that a salesman at REI recommended. They are Neoprene with wool lining and are AWESOME. Windproof and waterproof. Check them out at: http://www.komperdell.com/

I also have a set of Pearl Izumi barrier fingered gloves that are warm and roomy. I've worn those down to freezing temps with a set of glove liners. My only complaint is that when it's warmer, say 40-45, they can get a little sweaty. The Komperdell's seem to be more breathable and have a wider temperature range.