Then you want to have your show laid off to HDCAM. Your best bet will be to contact a local post house that has a Final Cut system and has, or will rent for you, an HDCAM deck. They'll talk you through the process, which will probably involve outputting a Quicktime movie of your whole show on a Firewire drive and taking it over. They'll load that move up on their Final Cut system and lay it off to tape for you.
While you're at it, go ahead and have them do it twice. You can send one tape to the festival, and keep one as your master. If you want to do other festival submissions in the future, it'll just be a dub, which will be cheaper and faster than going through this process again.