XF 1.5 Need assistance with a floating header image

[Highcommander]

Our site would like to use a "floating header" style image such as can be seen here: https://forum.thehammermc.com/

Our current site can be found here: http://www.synexmc.net/index.php

Can anyone point us in the right direction on how we can achieve this?

 

[Bart23Sept]

I thought that the floating header was a cool idea after looking at the site you linked to but after a few pages of having it bobbing up and down at the top of the page it got a little annoying. Great design work though.