Build a Website with possibility to build a mobile app after. I`m really after a confident developer for ongoing development activity

Looking for a website that will have a customer experience for logging in, subscribing and making bookings. There will also be functionality for members to post products within their subscription that other members can purchase. The website will have a good but simple client experience with server requests designed in a "push" type architecture. Would prefer developers that have experience in micro-system architecture and new web technology. As a second stage, this product will require similar functionality on a mobile app so should be compatible as such but not in scope for first cut. I would prefer that you are skilled in Xamerin to take this project on. Will most likely be hosted on Azure. The developer of this application will prefer an agile method of practice where stages of the project will be broken up to support the budget. Please do not submit a proposal if you cannot work in weekly or fortnightly iterations as everything discussed will need to be deliverable and delivered within that time otherwise the project is off. I am fair and well equipped to negotiate the scope of what is to be achieved in those iterations.