Could you check this link: http://www.google.com/search?hl=en&newwindow=1&q=web+design+directories&btnG=Search
Well here is a list of UK based directories, see if that helps. Or you could look at all possible niche directories out here, sorted by category.
Here are a few website design directories. There is also a webmaster niche directory list on the site. Some of those might have a design category.