I've been using oscommerce most recently, but have been unhappy with their search engine friendly url contributions, which seem buggy and poorly supported. I like their STS(v4.5) templating for the most part. I'm looking for a php shopping cart that has excellent capability in both customization of the url and flexible templating. Being able to keep both the look and feel of an existing html-based website, along with the url structure would solve a lot of problems. Being able to style something css based rather than oscommerce's table based structure would be wonderful. Any recommendations?