Is the smoker going to be out in the weather? If you can keep it out of the rain so water doesn't get in, go for it. If water gets in your firebox, it's not going to last very long.
I can see the interest in them but would not put one in if it were me. Not only are they too small to cook much on, it is impossible to regulate heat, can't be used when your cook chamber is full, and it ends up being another area for heat to leak out.