Design of an online shopping platform

Back to school shopping for books and stationery comes as a booklist given to parents by their respective child's school at the end of every year for the following year's class. All items on it especially the books must be bought. We wish to offer an online platform that allows the various schools (300+) to upload the list, parents to access the list relevant to their child, make an order (to include covering and delivery if desired) and submitting it to a bookshop for pricing and invoice generation. Payment is done via mobile money transfer. Currently we've been having parents scan and email us the list for which we then send to a partner bookshop, who revert with an invoice for parent to pay. We now wish to make this a seamless end-to-end service hence the platform. When a parent submits a request it goes straight to the bookshop and we get a copy. Please note that we are not a bookshop and in fact do not store any books. We just wish to transform the traditional go to bookshop, queue, pick books from shelf, queue again at cashiers, pay, go home and begin covering books. Examples of such existing platforms are welcome too. Visit us on [login to view URL]