Itsme, did you attend the Lake Washington contest? That one is a very nicely run grassroots contest. Out your way the NWL is the biggest sanctioning body that supports wakesurfing. In fact, the NWL nationals will include wakesurfing and is the only sanctioning body that has a wakesurfing discipline.
I have all the rules, scoring, etc for putting on a contest. Also, NWL has a step-by-step checklist for putting on your first contest that will guide you through the whole process.
In the AWSA rules I refernce above, we give the organizer (you and your wife) the flexibility to add divisions for surf, skim and longboard as needed. For the most part, in a small grassroots contest you probably won't have separate skim, surf and longboard divisions. Most small grassroots contests are split upon gender, age and skill level.
Shoot me an email and I'll be glad to send you the rules as an attachment. Also, I can put you in contact with Tom Regan who organzied the Lake Washington event, Chris Walker of the NWL and our very own Ed Sullivan has extensive knowledge of the ins-and-outs of staging a contest.