I've also decided to get the Penguin cups & balls, & Carl Andrew Table Hopping Cups & Balls. Are the kids able to see cups & balls at a show.
(From my experience) Young kids don't fully understand some aspects of the cups & balls. Having said that, you still get a good reaction with the surprise ending. But for the most part they don't understand!
If you have a fairly easy to understand routine and something they can follow it should go down ok. Another idea is to add a story to your routine, this would make it more interesting and easier to follow.
Carl Andrews - Table hopping cups & balls.
In this DVD Carl teaches his Cups & Balls and sponge ball routine. I don't think either of these routines are suitable for kids and therefore don't recommend this DVD. (the routines are for adults) What you learn is a routine, not the principal of the cups and balls.
(Example: If I want to play the piano should I learn a tune or should I learn the keys? If I learn a tune I will be able to play that one tune, but if I learn the keys I will be able to play many tunes).
Do you see what I mean? The same goes for magic, if you learn the fundamentals you can do many routines (even create your own) if you learn a routine you can do just that one routine.
If you want to perform cups & balls get something like: Michael Ammar - Cups & Balls. This will go through most of the fundamentals and a few routines!
Young kids will get the cups and balls if you perform it correctly. For instance... Some of you know about my mouse routine. That goes over really well with kids, especially the live mouse production at the end. I have the routine fitted so that it can be done with a 3 cup set or a chop cup. Both are successful with kids. You just have to degrate the effect or improve upon it well enough that the children understand what is going on, and then you are good to go!