B2B Pick/Pack Solution

I work for a small Vitamin manufacturing company. I was originally hired on as a Product Label Specialist, but after discovering my web design and programming background, I've been assigned the job of updating our entire website. <gulp>

As a general forward, I want to make clear that I had no part in the development of their site thus far. That being said,

We currently have a Business to Customer Interface that uses a pre-built shopping cart that goes directly against best practices disclosed in Amazon's now-invalid one-click patents which became public across over 2000 through 2004. The code must be from the 1990's, no AJAX is used, and its done entirely in CGI.

We also need to create a Business to Business portal where we can sell our prescription products. The goal is to have the B2B portal solicit sales for all of our products, with the first iteration emailing us whenever someone places an order, and allowing for automatic reordering. The second iteration should directly import into our accounting systems, debit the cash, and directly print a packing slip for logistics.

I need recommendations on what would be the most cost and time-effective solution for our problem. I'm not sure how time-sensitive the project is but I am the only person at our company who is capable of the coding/hardware setup, and I've never successfully set up a B2B pick/pack. Our attorney used to be a software engineer and successfully set up a similar b2b pick/pack, but he does not have the time to do it himself. I welcome all serious suggestions

Thanks in advance.

You're probably going to have to build this one... it's such a specific business domain, I doubt there's an existing open-source solution.