Graphic Redesign and Intergation of our OSC Jewelry Store

I am running a jewelry online store templated by oscommcerce. I am not satisfied with the current design for my store, and need to change a more professional skin and redesign of our logo. I require you to integrate this new design with the currently running website, wihtout damaging all data including our product and customers'data. no affecting our online business on line. We need a very professional freelancer to do this poject. Free mockup is preferred. The delivered time is 7 days.