Hallmark, Rysher and... Fireworks. I believe Fireworks was simply created as the production company specifically for the series and dissolved after FX was cancelled. You also need to take in account . . . CBN? I think that was the Candadian network that was part of it when it originally aired. The series was a combi-Canadian/American production.I recommend keeping an eye on Canadian DVD releases as well as American. You might periodically check in with amazon.ca - Yes, Canada is also region 1. They got Due South well before we did. *shrug*
*slipping back into lurkdom*