my smoker is homemade.it is 4' wide , 3 1/2' deep, by 6 1/2' tall.it is made from heart cypress , with 1' styrofoam over that, then wrap with sheets of tin,it is very tight,holds heat and smoke really good.I have a long probe themometer so I can watch the temp. inside the smoker.I also have one with the long probe inserted into the heart of what ever I am smoking,it is a preset puter type.I set the internal at 155 degrees,and it alarms when it reacher that temp. it tells the temp inside the smoker also.it also has a running clock to tell how long you been smoking.
I use green hickory nuts mostly; when they dry out I put them in a bucket of water for a few hrs. to soak.sometimes when I can't get the nuts,I cut a small tree(about the size of a tennis ball) cut into 3" cuts and use that.
I have a small door in the bottom so as not to open the big doors and let the heat out.I use a large castiron pan,put charcold and nuts.I also have a heat unit from an old store smoker.you can se it ine the bottom of the pic.that way if I leave it will come on if the temp drops below 145 degrees.

#1 shows the extra heat source.



#2 shows the racks.



#3 shows the heat door and stack.