Custom products dinamic box in osCommerce home page

Hi, we need a custom box in the oscommerce homepage of the site [login to view URL] The layout and field information is in the attached file. The box has to guide the user into a series of detail, that change the follow steps. The first chance is: online buy vs quotation request. In the first case the form has to follow the catalog categories and send the user to the right category page. The last category has to be showed, for examples the page [login to view URL] In the second we ask to the user some questions to understand the request. The form (questions) has to follow the subcategories of a particular catalog category or a new part of the backend has to be writed to allow us to modify the requests. At the end of the quotation request a lightbox-style popup has to appear to ask the contact information of the user. In the attached files there are the layout and the forms. At the end of the process two mails have to be sended to the customer and the administrator. In both the case we need an extra form with the "model type" selection. This is only a customer facilitation and it has't to produce any effect.