Rear: I would go with something like a pair of Planet Bike Superflash, use their seatstay clip. Maybe a 3rd zip-tied to the back of your helmet. Bring them in during the day if you want to warm up. Unless your commute (round trip) is around 2hr+, high capacity NiMH should be adequate and I would look at something like the Dinotte 200L AA-version; either on helmet. A secondary battery powered light for backup. Again, I'd bring them inside so they can warmup during the day; carry a second holder of, perhaps single use Lithium AA cells for backup. I think a Dynamo would be overkill.