Hey hey,
I have a ten-year-old son who is obsessed with Youtube and has a voice that would be great for a voice over, I've been trying to get him into it for a while. I know he's bit older than what you are looking for but he sounds like a 7-year-old, with a better vocabulary. Drop me a line in the chat and we can further discuss the project, I know he would love to do this.
Thanks for the consideration and I hope to hear from you soon!
Wolfgang Shanks