Convert Zen Store to OsCommerce

I have an existing ZEN store which i would like transferred to a OSCOMMERCE store. However, all of the following MUST remain... - orders / order history - categories - products - images - customers (passwords not important) All products should remain in the category at which they are now. Plenty, and i mean plenty! of work following succesful completion of this job. SMALL budget, quick timeframe. Thanks