Build an online catering system on an existing Wordpress website

We have an existing Wordpress website in which we now need to create an online catering system. Summary of steps: 1) Customers can view variety of menu packages 2) Have the option to download/view or order online. 3) Ordering online would be like a checklist. Example: [login to view URL] 4) - If customers need to customize their menu or have any requests then there would be a *__box to write in their messages.__* 5) Add-ons and other options to add items (the prices would change accordingly) in the same page or the next page (like most airlines online booking methods) 6) There would be an info sidebar always showing in brief what they have selected so far. (Like in [login to view URL]) 7) Final confirmation page with summary of orders and costs. 8) Customer can register or login with their social media account eg. FB & Google accounts. 9) Paypal or Bank transfer payment. 10) The necessary invoices and order confirmation to be emailed to customers and admin will receive email notifications and order can be retrieved and processed e.g. confirmed order, process, etc. We are looking at about 5 types with 3 different packages varieties in each type. (around 13 packages altogether).