Multiple children and staying calm

Our 9-year-old boy is a very inpatient person, the type who will keep everyone waiting for ages till he does what he is told or comes into line ready for the next step, but then as soon as he is ready, he is instantly impatient with those he has to wait for, even if it is mum. The thing is if he is waiting, it is normally because others who waited for him have had enough and are now playing up, or if its mum or dad they are sorting something out with the others (the ongoing line up of corrections etc.).
He is a very determined boy and full of ideas of what he wants to do, but everyone else should want to do it to or get left in the dust. He is quite intolerant and impatient if he doesn't like the choice made for things like a family activity. He will complain etc., Our Oldest son's turn of choosing the activity, was to all work together as a family, making wooden stools, he was complaining that the family activity was boring and no fun at all, all the others were really enjoying the team spirit in working together on this project. Dad gave him an instruction to sand as many pieces of wood as mum, or he would have to stay and finish when everyone was gone. He quickly got to work and soon had done as many as mum, I believe he felt some satisfaction in his task, when he finally decided to get properly involved. This is so typical, other times you give him an instruction, he shows extreme frustration or ignores you, so you say, "just now" and he jumps in with," I will, I will" and changes his attitude, says "Okay, and quickly does the task and checks back. But his heart is not changed he is just so impatient that he is saving himself more frustration. He ends up taking so much time all the time but never really getting through the rule of 3.
He has often exclaimed in a fit of annoyance or frustration, e.g. "I'm sick of this!", "Stupid system" or "it's such a waste of time." normally under his breath, so he is not really coming to the party on it, and getting any blessing from the system yet.
It's very hard to figure out what to write to get across his behavior, I just wondered if you had any idea's that might be able to help him and us as parents.