Create a Script for Big commerce

We need a program which would reside on a separate server (we have the server) that will take products from one of our sites, and transfer that listing to the other site. There would need to be a database listing for the categories that would map the category from one site to the other. For Example: Site #1 has a Mug listed in Category "Gift Shoppe>Mugs" and is item #123456 We would run the script to transfer item 123456 The script would see the Category as "Gift Shoppe>Mugs", match it against the Database and see that category Maps to "Home Goods>Mugs" on site #2, and create the listing on Site #2 using that Category. All info would transfer including images, Options, etc. If the Category wasn't mapped, it would prompt us to enter the proper category, and add this mapping to the database for next time. The script should be able to go in both directions (Site #1 to Site #2, and Site #2 to Site #1)