Sometimes the answer you need is to the question you didn't ask.
Edit: I'll add that I've tried buying restaurant branded potato skins from the grocery store, and they were absolute crap, worse even than the frozen ones that the restaurant was microwaving.
I don't think there's going to be any way to buy what the restaurants purchases, unless you're able to buy in bulk, or find someone who's willing to sell you some that "fell off the truck"