Build an Online Store - detailed specs

Hi. Thanks for your response to my earlier project spec. I have received several inputs and reading them, i realized that more details on the project are required - so that you can know more and I can filter better. The project has the following modules: 1) Registering new customers and validating them with SMS; ID check leveraging the government's Aadhar database (Android, SMS skills) 2) Programming several databases (product db, order db, promotion db, etc.) and logic on the cloud (hosting knowledge + programming skills) 3) Obtain orders for purchase based on product listing on a mobile phone (Android programming) 4) Doing a credit check with financial partners 5) Creating a "milk route" of deliveries based on location/ maps 6) Make deliveries to outlets and verify receipt using Aadhar/SMS 7) Creating purchase orders 8) Financial transactions for these modules I have visios for these in terms of logic. I'd like to leverage existing pieces of open source code as much as is possible - so that we can be very productive - and make it a scalable program. It'll all be on the cloud. I'd prefer a fixed price for the project. When you respond, please indicate your experience in each of the modules (yes with examples, no) and whether you'll be able to leverage open source codes for the modules. This ad supersedes the earlier ad on the same topic.. Thanks for your time!