I'd stay with open. Either way he needs practice to be a good hunter, and in the long run there will be more interest and feeling of accomplishment if he learns with open first. If he learns optics first it will be a tougher learning curve to go back to open.
My brains way of thinking and what I have seen in the youth I teach. They all want the fancy stuff they see on TV, but really do very well with the basics. I just tell them you can't handle what comes with the "extras" until you master the basics.