Aaton and Eastman-Kodak teamed in the making of the Super-16 camera. Now, browsing the Kodak Motion Picture Product Catalog I cannot find that special black plastic 200 ft. spool as empty spool for shooting.
It is not traceable under Available Film Spools, either.
In case someone of Aaton, Grenoble, France or EKC, Rochester, NY, U. S. A. reads this: Do you really mean to sell camera and film but not that spool?!
Normally the spools are reused, Have you asked around at the film lab you normaly deal with? they may have a few that they can provide to get you started. I have also seen them on e-bay from time to time.
Several but not all of the Kodak stocks are supplied on these special spools. Unfortunately not Fuji.
I have seem discussion that if one loads film on them, it is best to let it sit a week as the film needs to become set in the emulsion out configuration or it will unravel. The spool flanges can come off to make it easier to load if needed, and I would not be surprised if you could get away with just using a core and darkroom loading if all else fails. The core is the same size as a regular core, but has the slots the flanges connect to.