Small CMS and maybe a little front-end development

I need a cms to edit content in various panels on a page. As well as a registration page and a blog-type message board page. I've created the templates for these pages so they are ready to go. The main page with the various sections contains iframe sections (I used this method as its the only one I know how to distinguish them from each other) where the content is updated on a regular bases (see image attached.) There are about seven editable regions on that one single page. They are mainly tabular data—text update, pdf/doc/img attachment for download.