An hour show with that age's attention span? Good luck you will need it.
I would stick to strolling or no more than a 20-30 stage minute show tops. I did a lot of kid's shows when I first started out and many were nightmares. They get very restless and storm the stage after your props, sometimes they even break them. These days luckily I don't have to do them much. I get a lot of requests but for me they are the least fun and the lowest pay. I won't do under age 12 or so now. I am also a more serious adult performer and I don't like trying to act like I am in a play pitching a storyline in a strange high voice.
Most great kid's show performers do those shows exclusively as it is in art in itself. It is good experience but you need certain types of magic for it. Generally close-up "Street magic" does not work well with kids. They don't understand it. They would rather see sponge bunnies and comedy props. But I think you will just have to experience the nightmares yourself to see. I would buy Silly Billy's book and DVD at LEAST before doing any kid's shows.