Wow, those are really nice, scott. No, there isn't much info. on building your own panniers on the net, but their is TONS of info. on making your own backpacks. Many of the same priniples apply. The materials used are the same. Make a backpack, throw in a hardback, slap on some Arkel hooks and your set.
Quest Outfitters sells outdoor materials. If you are interested in making a pannier from scratch then this is it. Check out thier G4 Lightwieght Backpack. I imagine the design could be changed for panniers.
Remember
Heidi Domeisen? She made a lot of her own gear prior to her tour from North Carolina to Alaska and back.