I made a site with dofollow blogs and forums, the are 99% dofollow. At the moment, there are more than 200 dofollow blogs. Soon, all blogs will be in separated categories and registered users could vote and report non dofollow sites... Unregistered users can see just a few dofollow blogs... http://www.dofollowsites.com
If you have a long list of blogs, it would be better if you can create a custom search engine as well in order to allow visitors to search quickly.
Check this out www.dofollowwebsites.com. make a custom made search engine like that. would be good i believe.
I think you should definitely give your users the opportunity to search for do follow blogs on your site. I think you should add more colors into the color scheme and add some graphics to the page.