An E-commerce shop with backend and frontend.
Frontend = for customers (B2B + B2C)
*for different admin with different access levels
*for a couple of vendors, which are able to upload there products with a couple of information
Vendors given price + Logistic calculation + margin + vat(for B2C)
It could be used the open source "oscommerce". It need to be modified in the database structure and in functionality.
(More detailes available, if interested)