Build a online store

Building online store. Initially we are going with promotion offers. So no uploading of products. But We should have an option of uploading the products to all departments in future. As of now we will keep all departments as launching soon. Once customer selects the promotions then he has to sign up for account then check out and payment page and order creation. Back end we should get order creation copy and customer should received order confirmation through email and sms. We require content writing. Payment gateway. Chat support. Please note website should support large loads of logins at a time. Without getting slow or down. We need support for 30 days. Website should have fresh look and genuine. First impression best impression.