Custom Build a Trailer

I want to build a feature that is similar to building a car on such large sites and [login to view URL] or chevy.com. I have a descriptive graphic mock-up that can be viewed at: <[login to view URL]> I would like to do via asp.net VB and ajax possibly to prevent several calls back to the DB being required. The data originally will be populated via a DB and then handled from there. I believe the graphic layout above should be a good description of how the project should be created. Also I am very proficient in HTML/CSS so no major graphic or formatting will be needed as I shall handle all of that once the project has been completed and handed off. Thank you.