Build a Website

We are needing to create a web application that has multiple types of permission levels and portals, sell and keep a large inventory of sold and unsold product. Our company will be selling to membership groups. So, we will need these permission levels: 1) Administrator (our company) - can view all, can manage inventory, POS, support channels, etc 2) Group Manager (the managers of the membership groups) - can see members of only their group 3) Members (the members of each group/individual people) - can see only their own profile, products and history. --The member portal would also need to be available as a smartphone app for iOS and Android. I feel the most comparable website to what we are wanting is build is [login to view URL] where that are homeowner levels, local partner levels and of course [login to view URL] employee levels. We also must build a robust inventory management system and POS system that automatically speak to each other. We expect to keep 10,000+ pieces on hand at a time and each will have its own serial number. The POS system needs to be available from all 3 levels. It will need to integrate with a payment system like stripe. We'd like to be able to embed this order form on other sites as well. Finally, we plan on a support ticket system like [login to view URL] to manage our order fulfilment and support channels, so we would need these programs integrated into our site. We would need this to be built with the most modern of development styles. We plan on providing the branding and imagery. Once selected, we will provide a few samples of how we would like the development to look. Thank You!