Build a Website on Magento Platform

We are looking for Magento specialist developer/company to build us a new customised website for our e-commerce brand. We have 3 store fronts and 3 levels of customers, we do B2C and B2B. Things we are looking for: 1. Better wholesale checkout experience - ability to order many items at once 2. Better retail checkout experience - drop down shopping cart 3. Back end accounting 4. Easier product upload and inventory management 5. Ability to sell at conferences through Magento using square 6. New look and feel 7. Mobile responsive 8. Faster page loading 9. More shipping options for customers and wholesalers [login to view URL] pages like: Press, Look book, Testimonials, Blog, etc [login to view URL] Website content, SEO optimisation [login to view URL] way for EDM campaigns and promos [login to view URL] - data extraction and use