It's a pretty cool grill for sure. I like the idea of converting it to a smoker but see a couple challenges...1st is that the lid open at the center of the barrel. It would let all the heat out when open and if you wanted multiple racks you would have to come up with something unique to hold them up. The other challenge would be installing the chimney. These aren't insurmountable challenges, but they would make for more work.
Good luck!