What can I substitute for Rice flour in a gluten-free pizza? I am going to try to make gluten-free pizza for my wife, and I'm going to start with this Serious Eats recipe.  

The recipe calls for white rice flour, but my wife has just about everything EXCEPT that.  She has:  corn, oat, potato, rye, sorghum, soy, and tapioca flours.

Which of these (if any) can I substitute for white rice flour?  Or should I just go out and buy some?



For posterity, the recipe is:


1 (7.5 ounce) package Chebe Original Bread Mix (not Pizza Mix)
1 cup white rice flour
1 teaspoon baking powder
1 teaspoon salt
3/4 cup water plus an additional tablespoon or two, if needed
2 large eggs
2 tablespoons olive oil
I would go out an buy some.

Dough textures for gluten-free breads are fragile and the result of extensive testing with various non-wheat flours (at least, good ones like Serious Eats are).  None of the other flours you have available will have the same water absorbsion or starch content which rice flour does.  If you substitute, you'd have to make the recipe several times in order to recalibrate it.

Besides, rice flour is generally pretty useful if cooking for someone who can't eat gluten.  So you'll use the rest of it.  And if you can find it in a bulk foods store, it's quite cheap.