Substitute for pastry flour
Without knowing what you have available, it's difficult to give a recommendation.  The common substitutions are:


a blend of all purpose and cake flours (either 50:50, or 5:3 favoring the cake flour)
a blend of all purpose flour and cornstarch.  (2TB starch to a scant 1 cup of flour)


The first one will give you closer to what you're looking for.  The second one might not be quite as tender.