I use Semolina flour. There is a Farmers Market in Plano (Sprouts _ all around the Dallas Metro) that sells flours, sugars, etc. in bulk form for a very reasonable price. I usually pick up a few lb's of the bread flour and semolina when I stop in.
I for one have fell victim to the stuck on peel/board serveral times in my early baking days and have completely ruined pies so much I had to make a ripped calzone, or what appeared to be. The temperature of the peel/board or whatever you are using probably would have sometihing to do with it if you are not using a course flour i.e. semolina, corn meal. You also could prebake the dough pre-toppings and that would most likely knock out the sticking issue as well as not over topping the pie.