Build an Online Store with an excel ordering form and strap ordering form

Hi, we need an online shop that would allow us to import and export products with excel. It has to have mulitple levels of price range. And a price range with all prices set to 0. Important is the ordering part. For batteries we need all to look like an excel file... for strap we need a specific look. attached two files. We need to mange users. To upload and download them so we can give easy access to new ones. It is used only B2B store no end customers. All customers are known. We need a modern look and a site wich is compatible with mobile phones and tablets. The site need to be very simple for usage. Fast orders. Short step. Just login and insert orders qty. then a button finish my order. Very easy and fast usage for the customers. The site need to be easy to operate. Add new products and upload their data, prices,... We need a simple system to manage it. Also the site need to be closed. So only the members that have aproval can access it... Pictures need to be copyright protected. Site must have mulitanguage. And we need also a photo gallery like a showroom. And some additional options will be also probaly needed. What CMS system would you suggest to use?