I have been using a pannier from Arkel for about 3 years now. It has seen all sorts of weather, including winter, and it still looks and works like new. They have a large range of styles, including an "Urban Commuting" line, which may contain the bags your looking for. They are pricey but IMHO are also worth every penny. I have the "Commuter" bag and I am very impressed with it.

http://www.arkel.ca/ca_e/all-categor...e-pannier.html