Peter Springwald is the head of officiating of IFAF (International Federation of American Football).
http://www.ifaf.info/ He might be able to help with recommendations about someone to give a clinic - he can put you in touch with Olivier Valongo for example, if you needed a Portuguese speaking official....
I won't put Peter's email directly on here in case it gets picked up by a spam engine but you can mail Peter by going to this page
http://www.gfl.info/text.php?Inhalt=newsmeldung&ID=2555
and clicking on
Bestellung an Peter Springwald
The IFAF website has occasionally interesting world-wide stuff about AmFoot. For example I didnt know that a league had just started in Israel, in their first game, Big Blue Jerusalem defeated the Dancing Camel Hasharon Pioneers.
Try writing small enough to fit Dancing Camel Hasharon Pioneers on your gamecard