I have two. When Brooklyn (who is now about 5 lbs or so) was a puppy we put him in the bathroom when we went to a concert. Well, he barked loud enough for the neighbors upstairs to complain.
What I'm getting at is you can stop him from barking when you are home (which would still be noticeable to your neighbors) but you have no control over what he'll do when you aren't home. Also, what will you do with maintenance people and such? They don't always let people know when they are going to show up. I'm allowed to have pets in my building, but it's still a big concern of mine.