Build a Website to sell Software

I need a website to sell software. It must have a back admin panel to control customers, sales, invoices and newsletters. It must have a way to allow customers to test the software. After customer test software they can buy it, after payment is confirmed the software can be download it from a sub domain secure [login to view URL] the software website will have links such as: Home, About us, Request Demo, Futures, F.A.Q, Support (chat room) and Contact us and at the footer: About us, privacy policy, terms & conditions and the social media icons/links. More details will be given to developer ... It must work with [login to view URL] and Paypal for payments..