We have a business customer who has his own website similar to ours, whereby we will act as his supplier. His customers will order from him, and he'll order the products from us in a weekly order. His site is osCommerce.

An important issue: since we need to pick and pack each order individually, we will need the orders to be divided by customer. Therefore, we need to import both the customers and the order information into our system from his system.

The database structure of order related tables seems similar between Zen and osCommerce. Any advice on this kind of issue, obvious or not, is appreciated.