To have a Contact Us page in the storefront that is a web-to-lead form and has the same look and feel as all the pages in the application, the requirement can be fulfilled by creating a Subscriber Page (CC Page). This is a custom Visualforce page that can be added to the storefront and use the standard header and footer components. The page can also include a web-to-lead form that submits data to Salesforce as leads. Salesforce Reference: B2B Commerce and D2C Commerce Developer Guide, Subscriber Pages