I thought about looking for an old style pizza oven, but I think I'd rather use it for pizza.
The only reason I'd build one is that I can make it exactly to the size I want and maybe even make it expandable.
BTW, the one thing that will be a little difficult to get is the insulation, thought that on the off chance Homely Depot might have some high temp insulation, but no luck there. It looks like the guy who made the oven with soft insulation used stuff that was good to 1000F, you definately don't want to try this with standard houshold insulation.
Ron