How are going to fire the metal pizza oven? Propane or wood? There is a restaurant in Burlington, VT that uses a wood fired pizza oven and the pizza there is the best I have had. Being east coast Italian, that says a whole lot.
While the metal does not seem to be a major problem the fire brick probably makes good sense except for cumulative weight
Make no mistake, there ain't no powder in this Puff ! And... I'm not really a crazy person but I play one in real life