Interesting panniers, Scott.
I have ideas about design, but I'm looking for information regarding material, zippers, etc., as I have NO idea where to buy that stuff.
Right now I have the panniers I need, but my set of Arkel T-42 will need to be replaced soon. The structure is still very good, but after 7-8 years of year-round use, the fabric is worn and one zipper is really cranky. I am thinking about rebuilding them onto the same frame.
If I do so, I might use waterproof material on the top and front surface, which would keep the content dry when there is just a mist of water.