I can understand why you'd want the media boxes to be static, but understand that a <frame>s/<iframe> structure brings its own unique issues. For conventional websites, the main reason this kind of structure is a problem is that search engines largely operate in terms of individual documents/pages. So should any of your pages happen to appear in the search results, the users will either be sent to the info page itself without any of your other intended structural elements, or they'll be sent to the site's main page and they'll have to navigate through the site to find the information page they wanted to see. So, at the very least, you'll want to make sure that all of the info pages have a link to your main page so they can re-enter your site the way you intend. And keep in mind that if you use <frame>s, any bookmarks they try to set will be set to the main page as well.
If these issues don't matter that much to you, then it doesn't matter that much what you choose as long as you use valid HTML mark-up and create a site that people like. You'll just have to put extra effort into promoting it outside of the search engines in order to generate traffic. Good luck!