Smokeless Wood Fire Pit and Natural Gas fire pit

I spent a lot of time researching ideas to try to incorporate into my smokeless fire pit when burning wood. The ideas I used in building my smokeless fire pit have far exceeded my expectations in how well they work.
I initially took the idea of a central air inlet from "How to Home" - • Can the Smokeless Fire... . After I looked at a Brio pit at a local hardware store, I realized a central bottom air intake is one feature they use to help with smoke.
I bought a 30" metal insert from Amazon (www.amazon.com.... Since I wanted to incorporate a double wall as the Brio pits do, I needed about a 32" inside diameter for my pit. It turned out when I drew it in Sketchup that 4 retaining wall blocks and 4 cut in half with the same angles on both sides of each half yielded me about a 32" interior diameter fire pit.
I set this fire pit up however with a natural gas line also outside of the fire pit so that a portable natural gas fire pit can be used instead.