The featured SuCasa My City Website is a standalone site to help with site design and a template to apply to other pages.
You will not be able to import this layout to SiteAssist. To check if a SuCasa layout is compatible (able to be imported) with one of our products, you can check the Compatible products section of the SuCasa Details page for the layout. You can get to this page by clicking on the info (button with "i" on it) after clicking on a SuCasa layout.
Here is a direct link to that page for the layout you are asking about: