Need a large image in header

I would like to have a large image in the header area of my homepage. I need the navigation buttons below the image, so I selected option 2 of the main header layout. I still cannot get the buttons under the image. I have tried setting the image as the featured image, and resizing the image as the logo making it large. Can you tell me the best way to go about this?

ecosignsandbanners.com

Thank you!