Actually, on studying your current site, it would not be difficult at all to achieve the same look with ZC. I have reworked my own site to have no top header, with all header/nav functions in the left sidebar and content on the right.
You would want to replace the blog and calendar frames in the sidebar with cart navigation boxes for the commercial side. There are some css tricks to get background images for dynamic content like boxes that change size based on content, but they won't be hard to get for one who has mastered databases ;)