Data-driven form/application

I am working on a Drupal website that needs a good, reliable, and fast data-driven form - similar to [login to view URL], [login to view URL] or statefarm.com. Although it is not an insurance quote website, it essentially has similar attributes. The objective of this platform is to allow visitors to complete a brief form that will populate a quote. The form should be displayed on the front page. Visitor enters one or two sets of values in the first form field (i.e., [login to view URL]). Visitor will then click 'next' or 'go', where they will be required to answer additional questions. Some questions may hide or unhide other fields based on visitor’s selections (i.e., freelancer.com/buyers/create.php). Once complete, visitor will click ‘get quote’ and a quote should be displayed. Once the quote is provided, I will like potential buyer to select from additional services/products options – i.e., [login to view URL];c=us&l=en&s=bsd&cs=04&model_id=vostro-3500. Of course not as robust as Dell’s but similar in functionality. BTW, this is a secondary component – it could be added in a later phase. Thanks