Need visual designer/themer for Drupal nonprofit site

I'm 98% finished building a nonprofit's site in Drupal. Now we need an individual or firm to execute a visual design and Drupal theme. We're looking for someone with a decent portfolio, and ideally a track record working with nonprofits.

We don't need development or site building/configuration help, just design/theming.

The site is almost complete besides the design/theming. Ideally we'd like to find an individual or firm who can handle the visual design and theming, but are willing to break those functions up if necessary or advantageous.

I'd like some advice from nonprofit site owners here – where do you turn for design on your Drupal sites?

Also, please advise if there are other groups this would be appropriate to post in. Many thanks!