Those Arc-Teryx ones look nice.
I've lived in all manner of cold and the two pairs of gloves I use consistently with my camera are firstly, a pair of leather gloves I was given for christmas some time ago (probably purchased at Sears or someplace similar. They aren't super warm, but, for me are fine down to -10/-15 C. I find the dexterity they give me is great. Also, the soft leather gives me a great grip.
The second pair are called trigger mitts. The pair I have comes from Newfoundland, and I've always associated that style with newfoundland, but I'm sure they exist elsewhere. They separate your index from the rest of your fingers, so you get a bit more dexterity than a full mitten, but still give you the nice warmth of full finger coverage. It's good enough for changing aperture/shutter speed once you get all the rest of your settings figured out on a shoot. Warm enough to get down to -20C and beyond (These were my preferred gloves in the -40 of Saskatchewan), but still thin enough to keep in your pockets when you aren't gripping your camera.