@nitis Why not get a drum? Look for one that you can put a kettle lid on..
Used Traeger go fast. Missed more than a few myself.
The PID is only as good as the smoker itself.
I fear that it will never stay at a low temp or run too hot..
Just too many gaps in there.
How hard would it be to mount to the bottom of a kettle?
You would need to get creative with mounting and supporting that fire box..