Magento: ADD PRODUCT form for products not in MAG's default database

Hi people. I have website based on magento 1.7. I need to have Add Product template (form) to insert into any page. For example, I have a page where users can view an online catalog which has products with the following attributes - Article, Page, Position, Type, Size and Price. The Add Product form hast to: 1. Collect the following USER entered information (Catalog Name/Website Name, Article, Page, Position, Type, Size and Price) and add it to the default shopping cart for checkout. 2. Product Checkout information must be attached to a customer purchasing the product(s), kept in database and seen in the Purchases at the Back-end of the Magento. Example of the catalog: [login to view URL] Example of the form (view side) is attached. I need somebody to develop the controller to add/update the cart.