For the CSS Products, you can create your site template design in CSS Sculptor, create the menu design using Menu Writer, then create your site using this design using Site Sculptor, see the "Creating a custom template for Site Sculptor" tutorial on the Site Sculptor Support page:
Dynamic Dropdowns can be added to the page after it is created by site sculptor.
Most of the extensions like DataAssist, eCart, Dynamic Web Charts, Google maps etc. are used to add functionality to the ages after they are created
The Web Development Workflow may help you: