That doesn't use iframes, it uses divs. One thing you can do is use server-side includes to include text into your page rather than iframes. iframes aren't supported by all browsers, for example, but SSI is, because it's server-side. Frames are generally evil.

I don't know of any way to keep the side bar but not the bottom one. Either you can force it to have both, or have it auto-detect, or force it to have neither. That's all I know how to do with CSS.