Are you looking for other instructor or Cathe only?
If you looking for Cathe's I would recommend: Rockout Knockout DVD or ICE Series Rock'm Sock'm Kickbox. I would try Cathe On Demand first and see if you like the workouts before you buy them. I believe Cathe has a 7 day free trial for On Demand?
I also would recommend:
Amy Bento Kickbox Surge And Core Refining Cia also love Amy Bento In the Ring/All Cardio Hi Low Knockout Cia 2805.
Ilaria Montagnani has a lot of great kickboxing workouts.
Susan Chung Rapid Fire dvd's are great.
Hope this helps.