Thats an interesting idea, the only problem i forsee is trying to place content asthetically anywhere near that design. That was the same problem I had with your first design too. You see, you are isolating your content from your header or navigation. Doing so really complicates the process of finding a good flow. In your first design, the header/nav span across the whole top of the page, depending on the size of the window, the width and height of the page will differ on every page view for every visitor. That means the width of your paragraph blocks, or content will probably differ unless you set a specific width, and if you do that then it wont look right when the page is too large for the block of content.
My design isolates the header/content as well, but not before setting some page parameters. The content is dictated to be the set width of the image + nav images, it gives you an out for the page size varience. It segways for nice blocks of text aproximatly 400px wide. You want to be able to:
A) Integrate content with the header/nav or
B) Set some page paremeters with the header/nav
Above all things.
Se what I mean?