new e-commerce website

I am looking to have a standard online store setup with shopping cart functionality. I need to be able to personally update the site content with descriptions and pictures on a regular basis. I am planning to start off by selling a small quantity of items (maybe about 20) and looking to expand that to a 100 items or so relatively soon so each item for sale needs to have it's own page once that item is drilled down on. It also needs to have the ability to accept discount codes and list promotional/sale items. Additionally, I need one page to be a blog. It should also be able to interface with a real-time (offline) inventory application.?