Web development -- 3

I need a new website. I need you to design and build my online store. Hello, I'm a startup ecommerce company, my platform serves as an E-currency Exchange or digital currency exchanger, where customers will get to see information of E-currencies in stock, exchange rates (buying & selling rates), and payments information. A customer who wants to buy or sell e-currencies will have to create an account on the website to be able to place orders for the e-currency they want to buy or sell, then fill in their e-currency account details, amount their buying or selling, then proceed to checkout. On the checkout page customers will have to choose which payment options they prefer, either manual payments or auto payments. For manual payment instructions will be posted.(Instruction for mobile money services, bank deposit). For automatic payment my website will be integrated to a local payment gateway provider ([login to view URL]) PLEASE TAKE NOTE. A customer e-currency account will be credited from a different platform NOT my website. I want a website implemented on a responsive front end, so the website will adapt for Mobile, Tablet and Desktop PC access. It should be built on a Content Management System which would enable me to manage sites content and set my exchange rates. The front end would offer users a calculator which can then be used to facilitate the purchase of bitcoins and other crypto currencies or e-currencies in either USD or GHS etc.