We bought the tux from gagas.com (they had a going-out-of-business sale, $15)
We also bought Nicolas a small sword pin to wear, instead of a boutinerre. It's similar to the pic below:
<-- we are calling him the "keeper of the rings", and FI has been teaching him what it means to have that responsibility.
We are going to have him also be the "keeper of the vows"... we printed our vows and rolled them up like a small scroll, and tid them to the pillow also.