Design a Web Site with an Ecommerce Function

I need someone to design a web site for a company that produces saliva based testing kits. Currently we are producing drug abuse test kits with saliva, but plan to expand to other areas of testing. We need our web site to show businesses and consumers who we are and what we make. We also need consumers to be able to purchase our products from our site. I would like for the programmer to use a proven ecommerce platform and not invent their own.