Nick, many schools of how to cook them but one thing is for sure. Keep your temp in the smoker at 225 or lower. I agree w/ Steve, you'll be looking at 1 1/2 hrs to 2hrs a pound. So I would plan more on the 12 hr time frame than 9 but that's me. Try to keep the temp of the smoker where I mentioned as the fat in the brisket will boil and the finished product seems more like a well done pot roast if the temp in the cooker gets to high or the internal temp goes over 190(I've done it).
Take it to an internal of 180 to 190 and then take it off and wrap it in heavy duty foil and put it in a dry cooler to rest for a few hours. Then slice it or shred it and enjoy!
Some guys like to take the meat to 160 and then foil it and put it back on the smoker till it gets to 190 but thats preference. I might try that next time but not foiling is just fine as well.
Give yourself enough time and be patient...by the way, tell your son thank you for doing what he is doing for us. I appreciate his willingess to serve his country...let him know that I sure hope his return is safe and speedy! I, like you Nick, am very proud of your son!!