I just found a old oil tank for FREE!! I will get pictures tomorrow. I was gonna grab the trailer and go get it after work, but I called and he said it was a 1000 gallon tank, and very heavy. Got there, it wasn't as big as he was saying. I came home and grabbed the trailer, and after work tomorrow, I go get it. Would have gotten it tonight, but my toolbox was in the way.
Here is ideas I have for it. Not sure which.
Flat:
Or upright:
First thing I think. Vertical setup gives more room for heat control with racks set higher or lower. Fill it with different items at different heights according to desired smoking time.