I don't normally respond to questions by saying that you need to talk to a lawyer, but in this case you should.
I don't know if you can do what you want, but I do know that if you do it wrong, you are going to create a big mess for yourselves. What if there are four of you, and three of end up not liking the fourth for whatever reason, and then you decide to reduce his share from 25% to 1%? If your company is ever worth anything, then be prepared for a big lawsuit.
Closely held (i.e., small) corporations have obligations to minority shareholders since the minority shareholders can't easily get out, and it is easy for the majority shareholders to take advantage of minority shareholders. Unfortunately, this is far too complicated an issue for a forum like this.