I have a great old oven it's a O'Keefe and Merritt from 1948 20,000 BTU burner oven. If you can find someone selling one of these old workhorses grab it.
My oven reaches 550 F in as little as 10 min preheat. What is really great is when cooking many pizzas the heat recovery is very quick. I use a pizza stone on a rack set to the lowest position and get great pizza.
I live in SF and we mostly have these old stoves becuase noone wants to carry them out down the stairs so we just keep fixing them. I have decovered them as awsome pizza ovens. It has 600F max temp.
What is even better is the thermostat is adjustable with just a turn of the screw I can go as high as I want. http://www.vintagestoves.com/stove/okeefe600/
this is what I'm talking about.