Just some extra food for thought, if you are thinking of doing the launch party, I would highly recommend having Craig Henningsen come out and do the party and seminar for you.  He knows exactly how to get, not only the kids excited, but the parents excited too.  He can also give you, the instructors, some good advice on how to keep your kids interested as well.  He has done this sort of thing all over US and parts of England and Ireland.  He is just a natural.  One of the most respectful and mature kids that I know.  If you are interested I would contact Sensei John Sharkey at Sharkey100@aol.com.  He can help you with that. 

Another bit of fat to chew, is arranging a time to come out and train for the weekend at Sharkey's Karate and learn some ways to work the different phases.  He has a basic blueprint that has been proven to be very successful.  I hope everything works out for you.  Keep me posted on how it goes, especially with the adults. :)