Customized Coding of a shopping cart software ( Online Store )

I will open an online store, My store idea is a little bit different than any other stores, So, what i'm asking here is customized store software or editing magneto cart to match my requirements, My store idea is that customers will use to order stuff they order by phone, like ordering food from fast food chains like ( Macdonald's, Burger king, Kentucky..etc) , Groceries from a brand grocery store ( Example: Walmart, Carrefour..etc ), or Medicaments from a Brand Pharmacy Stores, or clothes from a Brand Clothes Store ( Nike, Adidas, Timberland..etc). so my idea is, The customer registers and his address is stored, then for example he order a Macdonald's order through my store, The employee working to receiver orders in Macdonald's will have his own private admin panel where the order appears for him and then he begins the process of delivering it. so, every brand store will have his admin panel showing his separate private orders that he is supposed to deliver . And the customer doesn't pay me anything, my role is to present brand stores products to customers and deliver the order info to the brand stores. Also, i need the store to be integrated with facebook where facebook users can use the facebook applicated to connect with the store ( Optional but Preferred ) Thats just a general overview of what i'm expecting, i'll provide full project details when a deal is agreed. I'm flexible to negotiate the budget required.