You should also consider where you will be sitting in that room. If you are normally only six feet away from your fronts, a bookshelf would suffice as long as you have it mated with a sub. If you are 8 or more feet away from your mains, then a floorstander would probably be the way to go. I have a similar sized room, but the configuration of the furniture it so that no one is more than 10 feet away from the mains and use M22s as mains.