Many teachers take the time to provide something a little extra to a student whom they know is gifted, even if no program is being officially provided. And many parents provide outside activities and special learning fun at home to augment their child's regular education. If you have read some of the checklists on gifted behavior, and you believe your son fits the bill, I would go for it and have him tested -- though the school may not agree to do it.
Even an identification of giftedness does not allow for your son's "pay attention to me" behavior that you describe. A structured behavior plan in school where he earns points for not interrupting -- where points can be redeemed for fun things like computer time -- can still work at this age. Good luck.