Simply get a small outdoor clay oven, those work fine and are not that expensive anymore.
Downside is that it only does pizzas. No chance to do pizzas one night and then use residual heat for bread the next day, etc. If you have the means and space I highly recommend a real clay/brick beehive oven, but once you do pizza in a high heat oven you are never going to go back to trying to crank up the temp in a conventional kitchen oven.
Kamado cookers make great ovens, smokers, and grills.