A DIY solution might be something like this:
tn_pannier.JPG
You need
- one packet of 4 frame brackets, 2 inches
- 4 #8 bolts about 3/4 inches long (depending on thickness of fabric)
- 3 zip ties
- one bungee cord
Bend the frame brackets so that they form a hook that will just fit on your pannier.
With an ice pick or nail, create 4 holes through the back of the back. Put the screws through the frame brackets holes, with nuts and washers on the inside of the pack.
Push the twist ties through the fabric at locations that will hold a bungee cord. I didn't use (and don't seem to need...) a J hook on my pannier, but you could create one out of a wall hook for frames.
If that doesn't work, you can get pannier hook kits from mec.ca, arkel.com or from Axiom at your LBS.