oscommerce integration

Does anyone know of any plugins for integration with osCommerce? I have the looks & sidebars looking right for going between the two, but I don’t have functionality for the following: sessions, user accounts, product reviews from WP(?), etc. If there is no such thing out there, I will have to get cracking!
I’m not sure what would be the best way to integrate the two – anyone have any opinions? I see 2 options so far: 1) add the osCommerce session stuff to the ‘admin_head’, 2) add filter hooks at all points in WP that create internal links (seems like there are a couple of places that would require hacking the code).