Hi Alain
For the header you have 4 options:
1. Just to have the title of site and description.
2. Add a custom logo that will replace 1.
3. Have a header image that goes the full width and height of header.
4. Leave empty.
My suggestion would be to create a full width header image that is designed to contain both the logo and the title of your site to the header dimensions of the width (which is shown under Layout Settings) and height (which is shown under Header Settings). The header image is click-able to will always return you to your home page.
I hope this helps
Jim..