I am new here from a member perspective, but I gleaned a lot of good information off of these forums which aided me in building my smoker. Given that, I thought I would share my experience to possibly help some of you folks. Before I begin, please note that carpentry is not my strong suite. There is a fair amount of rework on this, but I am very happy with how it turned out.
The smoker is 3X5X6. I used 2X4 walls and secured it to 4x4 bases in case I want to move it. Steel roof with cedar siding. I lined the interior with sheet aluminum and used Reflectix to insulate it.
As you can see the smoke source is external with electric heat. I started with 1 element, but it wasn't quite warm enough. It could only hold the smoker at about 140 degrees. I added the second and it works great now. I did have to add another 4 foot section of pipe to ensure that the wood stove did not inject too much heat into the smoker as well. With electric heat, I can control it to within about 3 degrees of temperature variance. I'm happy with that.
Pictures are attached for those of you who are interested. If you have any questions, fire away. I'll certainly help where I can as many of you have provided me with information that I used to build this one.