As you may know, I am a member of BlogEngine's Team, I've made more than 10 free themes for BlogEngine, Which you can search and download them from your BlogEngine's theme gallery in the "custom/themes" page. Here is a quick list of those themes:
Also, I've made the BlogEngine's default theme for every new version, Which by the way, the latest one was the Standard-2016 theme.
Custom Theme For You
Send me an email with some basic information about this theme that you want. I'll design and implement it for you. If you have the design already, I'll just implement it. It will take 2-5 days with the latest technology and great quality and of course with a good price.