The more the merrier so I have easily a dozen different gloves and mittens. Full fingered and cut-off's unlined cycling gloves for summer use. Fox, Specialized and Oakley.
Multiple pairs of downhill ski gloves, lobster mitts and Gortex shells that will go over down mittens. My objective is to pick something that will keep me dry depending on the conditions. And I might bring a spare.

Yup - I have raynaud's syndrom too, but have noticed that keeping the extremities warm isn't the most effective strategy - at least in my case. I make a point of overdressing slightly so that my core temperature runs hot which increases circulation to the extremities. Yeah - I might have to deal with sweat a bit, but have stopped having to deal with finger issues in the winter. In fact - the last time I actually had a problem was at a beach after swimming for several hours - which lowered my core temperature and resulted in several fingers turning white in spite of the hot sun in the middle of summer. My current strategy at the beach involves a shortie wetsuit which seems to have killed the problem.

Gloves in general I find easier to cycle with. Mittens are warmer and a bit more awkward. A ski helmet and face protection is equally important. Its very easy to lose heat through an exposed head.