Have you tried making TV time, playstation time, video games, etc...his actual reward? Meaning, if you are good at school and at home on Monday then you can either watch 30 minutes of TV or play 30 minutes of playstation. As he starts to improve his behavior he can increase his time. If he gets in trouble at school or at home then he would not have earned any TV or playstation time.
Another idea is to completely clean out his room, all of his toys, tv, playstation, absolutely everything except for his bed, bedding and clothes...everything else has to be earned back and if you don't behave then you will do without.
This may sound a little harsh but from what I read it sounds like your situation is getting worse and if he is getting in trouble daily at school then you need to take fairly drastic measures and believe me he will start to care.
I also would cut out any and all sweets and candy if he gets any including any type of sodas, this may also help his behavior.
Good luck and trust me I know that it is hard, I also have a 6 year old who can be very trying at times and it is times like this that we need to remember that we are the parents and not the friend.
Good luck
M.