Im sure this has been asked a time or 2..But can someone tell me what gourmet cupcake shops use for flour? cake, self rising unbleached etc. Thanks in advance

they would likely use a variety of flours probably use all of those 

And some shops just use a commercial cake mix, then add flavorings to each variety.

and some use regular cake mix like anyone can get off the shelf from the grocery store -- there's not one flour or anything 

http://www.amazon.com/Conagra-Purpose-Hotel-Restaurant-Flour/dp/B0095FDIOQ 

I have seen with my own eyes how  cake shop owner in my city was loading about 10 bag this flour in their  van. They buy it at Costco.

If you're not using mixes, you use the flour called for in the formula/recipe.  My chocolate cake needs all purpose flour for its strength;  my white cake needs cake flour for its soft texture.