The gluten free TMX cookbook suggests that there isn't any one flour that substitutes wheat flour. A combination of 3-4 different gluten free flours will work best.
Option 1
250g rice flour
250g tapioca flour
250g cornflour
2 tsp potato flour
Option 2
200g rice flour
100g soy flour
100g potato or tapioca or maize cornflour
It also mentions using a binding agent such as xanthum gum and guar gum - 1 tsp per 400-500g of gluten free flour mixture.
