Prestashop Expert Needed immediately - New module wanted

Hello There, I have a default prestashop shop. I want a person to develop a module, where I can add ADDON/SIDE items that shows up to the clients during the ACTUAL product checkout. For instance: the product we are selling is Pizza(USD 10) which is a product under categories (default). Then Coke(USD 1) is a ADDON/SIDE item that is not listed under the categories>products but in the new module, which is recommended during the check out. So a customer during hte checkout adds this sideITEM/ADDON to their cart before finalizing the purchase. However, client can not simply add only the SIDEITEM/ADDON to their cart and check out. Thanks