I spent a bit more time on this site today. I have had the domain for a while and always wanted to have an affliate directory site.
The site is using a free script: http://www.cplinks.com/ which was easy to install, but could have some bugs in it after trying to submit a couple of sites. The interesting thing is that each time you update the site, you need to press a button which then re-generates html files for the whole site. This could work well for SEO.
The original template was pretty basic and I have gone and modified. I have used the colours from a free template and in my opinion looks ok for my very limited design skills.