The best GF pizza we’ve had is the Little Cesar’s GF Pizza kits. This is different than the GF pizza in their stores that are not celiac safe. The GF pizza kits can only be purchased as part of a fundraiser. The crusts are made in a celiac safe facility. They are not inexpensive, but are delivered quickly in a thermal box and come with the crusts, sauce and cheese and you can freeze the components to be prepared later.
I’ve purchased them online for a fundraiser for the Gluten Intolerance Group but I believe you can order them online through their featured fundraiser of the week.
https://fundraising.littlecaesars.com/products/15118