Well, if you want waterproof from a very proven name, you might want to add Ortlieb to your list. Their pannier bags are very highly regarded (I use a set, they're awesome), and it doesn't get much more waterproof than the roll-top closing system.

A 360 degree view:
http://www.ortlieb.com/spin/messenge...client=ortlieb
Product page:
http://www.ortliebusa.com/prod-53.htm

You can find them cheaper if you look around, too.