At an internship, I am tasked with setting up whatever PHP shopping cart me and my co workers think is best. I installed Magento, and it looks really nice, but it develops its own MySQL database. That's not necessarily a bad thing, but my job already invested a lot of time in implementing a system that automatically synchronizes a MySQL database with Quickbooks data. That database already has 1300+ items in it and is ready to go. Magento forums are saying that Magento is really stuck to it's own database.
Is there a solution to this? Can Magento Community be modified so it works with a database already in place? Or is there another PHP MySQL shopping cart out there that can work with item/customer database that's already in place?