This demonstrate the use of a BannerZest banner pasted into the Header area of a Sandvox Pro site. The banner covers the navigation menu if the bz.js file is edited in the way suggested by Aquafadas (See my BannerZest in Site Header HowTo)
This published version has no edits in the bz.js file on the server. The BannerZest banner is 750px wide. The HowTo is BannerZest Header Update.