best GF flour for a galette

I don't know if it's the best, but stuff like 1:1 and cup4cup are usually meant to be used just like flour, and Bob's Red Mill products have been good quality in my experience, so it would probably work fine. But if you're unsure you could maybe compare the ingredients to something like this: https://www.seriouseats.com/recipes/2016/07/best-gluten-free-pie-crust-recipe.html. I've never used this recipe but I love Stella Parks' gluten free mixes for cake, and I'm not even gluten free.