I don't know anything about Supercats, so sorry, I can't help you there.

However, it sounds like you are under the impression that you need a captain's license to go sailing, which is not the case. Yes, you should get instruction no matter what boat you choose and keelboat programs tend to be pricey (as are the keelboats you'd be learning on).

Some cat sailor in your area would probably teach you the basics of cat sailing for a pitcher of beer and some wings. Or if you want a certified instructor I can possibly help you find one in your area.

I may know somebody in the Chicago area I can introduce you to via the magic of email. PM me if you'd like some more info from me.