e-commerce with strong invoicing

[cajun67]

I'm setting up a website for a company that repairs individual auto parts. The way their store will work is a little different; the customer will take a photo of the damaged part, and open a ticket to request work to be done. They will then ship the part in, where the company will review the part and email an invoice for the cost of repair. Customer receives the invoice, logs into the store, and pays the invoice. The store will track the status of the part through shipping back to the customer.

 

I've set up a few e-commerce stores, but only more traditional ones (browse products, add to cart, checkout). What the client is asking for is an e-commerce package that can be built around invoicing.

 

Can someone recommend an e-commerce package (open source or commercial) for handling something like this?