GP Bikes sells them. Call or go see Tom (parts manager) and tell him Alon referred you to him (my name is pronounced most closely to a-lawn as in the grass in front of your house, not Alan).
These bags look amazing. Wish I would have known of them before. Been carrying a backpack to go to work the last two years because I was too cheap to spend for a rack on my Gladius. With this problem would have been solved. Did you say they were sold in store somewhere or only online? JP Bike or Royal Distributing have that brand?