My oven gets to 550F, so I just use it. Preheating is key.
I let my dough ferment in the fridge at least overnight for free-form pizza directly on a stone in the oven. Minimal sauce and toppings so you don't lose the crust under too weighty a burden. I also make Sicilian-style pizza in pans if I want to have more toppings. That dough is best a little wetter and right out of the mixer and into pans greased with olive oil.
I have a stainless steel plate the same size as my webber grill. I have had good results just building a good fire and slapping down the plate and baking at ~600F