Build an e-commerce website with EVERYTHING, including help

I am currently looking for a website design company that can design/build me an e-commerce platform to sell one product (pheromone cologne) at first and then possibly move into other avenues later in the site’s life. There will be a total of 5-8 pages, largely content driven, which will describe the product, research, and possibly host videos and feedback forums. I will be providing the content which will be on the site. Of course one of these pages will have the product purchase page that all other pages will link to. All major forms of payment need to be accepted, PayPal, major credit cards and some form of shopping cart. Also, some way of keeping track of inventory, and alerting me of sales and shipping address is also a requirement. I also would like email addresses with this site and some way of being able to update content when I need to without necessarily needing to contact your organization. Any way to have to an iPhone App tracking sales/inventory, etc? I would also like to talk about SEO possibilities and costing. I already have a domain name registered. Thank you and please let me know if there is anything I need to clarify.