Coupon Shopping Website Back End

I am looking for a coupon shopping website to be made (for a startup company). Think of Groupon and Wowcher, the website will be of a very similar structure. I will discuss what I am looking for with the developer and will discuss the structure of the website. The database should include tables for customers, businesses, products, adverts, coupons, promo codes, and more. The database should also have repository for images for businesses. The database/website should allow for users to login and have a login area: Customers, Businesses (with 2 types of users), and my company (2 types of users). Customers and businesses should also be able to login using their Gmail/Microsoft/Facebook accounts. Create the website, with basic functionality to : customer to view products, what they have purchased and redeemed, previous purchases; business to add products, adverts, view what sales have been made and redeem vouchers, add images, edit profile, request funds. Would also include a shopping cart, promo codes, simple reward scheme. Website to be developed using PostgreSQL and Django Python. The front end of the site will be built separately, to be linked by the back end developer. I hope to build this company further in the future, and would hopefully use the same developer for this in the future. As well as on other projects. English speaking is highly desired. I would like to see other similar projects that you have built yourself.