Custom PC, Parts E-Commerce Site

We are looking for someone to take a basic design that we will provide, and create an e-commerce site to follow that design. Would prefer an open-source solution such as oscommerce, but we are open to suggestion. We would like to be able to sell parts and supplies, as well as custom built systems. The choices for parts, upgrades, etc. would require dependencies for the systems. We would like something similar to [login to view URL] or [login to view URL], but with a slightly different feel. As I said, we will provide the basic design and graphics. Would like PayPal integration and an admin panel of some kind (such as with oscommmerce). Would like to be able to upload data and pricing from an Excel spreadsheet or CSV or similar. There will also be several informational pages, for which we will provide the content, including a basic support page which will take customer information (name, address, phone number, product, serial number, etc.) and forward that information via email to our techs. Feel free to PM if you have any questions. Will pay with escrow account.