I know some people slate mixed styles, but GKR Karate is very good. Its a combination of Shotokan and Gogu-Ryu and has about 60,000 members in Britain. There are many more thousands in Australia, New Zealand, and we have started some classes in the US. Its a simple(ish) style, and teaches all the basics of martial arts (discipline, honour, self-defense confidence etc.) but is not harsh for children. I have been doing this style for 6 years, and I am nearly sixteen. If there is a class near you, it would be a great oppourtunity for you kids...especially if they become an instructor in the US. We travel all over the world for Tournaments etc, and we can enter NAS tournaments. A list off all GKR classes can be found at http://www.gkrkarate.com