I have a 250 gallon tank my dad and I was gonna build together but he got lung cancer and past away end of last year. We didn't get around to building it. I want to build it now I just don't know what size metal to use for around the doors, expanded metal, what size angel iron to use for pull out trays for upper shelf, and how far down do I need to come down from top center line to start my doors? This will be a offset smoker.