I'm always having difficulty when developing gluten free master recipes. I've done lots of research and am unable to find a clear answer.
My favorite is:
1 cup brown or white rice flour
1 cup sweet rice flour (mochi)
2-4 Tbls tapioca starch
That should give you a really nice tollhouse cookie texture. Sometimes I'll increase the brown rice flour slightly (by 1/4 cup) if a cookie dough seems too wet.
As for pate choux, the same flour blend can give you decent results, but not spectacular. I'm still working on this one. I can tell you that increasing the amount of eggs (usually by 1) often yields better results.
Above all else, avoid using any bean-derived flours. They add protein, yes, but the flavor and texture will never be stellar if you use those. Stick with rice flours, millet, potato, and buckwheat.
Have you tried garbanzo bean flour? Potato flour? I use 25% rice flour in my shortbread cookie dough (it's not a gluten-free cookie) as well as sometimes in a pâte sucrée because I like its subtle crunch. But my crunch may be your gritty, and I can understand why you would want a chocolate chip dough that isn't that.
Here's my dough for churros. That's the most successful I've been with GF pate choux. It doesn't bake as well as it fries. Sorghum flour lends a slightly more gritty texture than brown rice flour, so you may want to use brown rice flour in its place if you're quite opposed to sorghum.
1/3 cup sweet rice flour
¼ cup sorghum flour
2 Tbls tapioca flour
½ cup water
¼ cup DF butter
1/8 tsp salt
Mix together flours in a separate bowl and set aside. In a pot over medium heat, bring water, DF butter, and salt to a rolling boil, stirring to melt butter. Reduce heat to low and mix flours into water, stirring quickly, until dough forms into a ball and butter seems thoroughly mixed in. Remove from heat. Beat egg in a separate bowl, then add slowly to dough, mixing until dough becomes uniform.