Hi Peter:
Most F2/Proflex plate bindings disks are interchangeable. All models (that I know of) have a rubber gasket on the binding that grips a smooth disk. There aren't any teeth, so angles are very adjustable. The only exception is the mostly plastic "Freecarve" and "Intec Challenge" models, which have a plastic toothed disk.
http://www.f2snow.com/english/products/bindings/freecarve.html
If you are looking for toothed disks, you may get lucky with another brand being reasonably close. I never found one, but I also didn't try that hard. I can tell you the Burtons, K2s and Salomons didn't work.
If you are looking for "press fit" disks that work with most bindings, good luck. They used to exist, but are now rarer than hen's teeth. I had a pair custom machined out of Delrin for about $50.
http://www.bomberonline.com/VBulletin/showthread.php?t=6352
Good Luck!