Reporting module for shop

I need the following for a modified shop. In the administrator: A module where the administrator can enter a list of products. Some of the products are available on the webshops, others aren’t. We need the following data for these products: Producs_model, description, brand, EAN. If the product isn’t available on the webshop, the description, brand and EAN must be entered manually. For the customers: Customers that are logged in to the webshop must add some data about their stock and sales to that list. When completed an XML must be put on an FTP server. The customer enters the DATE only once. Then the list with products appears, sorted by brand and products_model, and the customer can enter de STOCK and the SALES for each product. There will be around 40 products in that list. When completed, there must be generated an XML file. This file has to be placed on an FTP server. In the XML there is the customernumber, date of reporting and all the products.