UX redesign for news site overhaul

We are looking for an experienced UX designer to work on the overhaul of an existing Drupal news site. We aggregate a large amount of original and third party content, and need a design that enables users to interpret and navigate a substantial and constantly-changing quantity of content quickly. The deliverables will be psd files and wireframes. The design will be implemented by our development team, but a basic knowledge of Drupal layout principles (blocks, panels, views) would be advantageous. We're looking to redesign principally layout and typography. We will be retaining elements of our existing colour scheme and graphics. Navigation will also remain broadly the same although we are open to suggestions if you see the potential for substantial improvements in user experience. Please submit details of your portfolio, we are particularly interested in designers who have worked on news sites with a large quantity of fast-moving content. We can then take the conversation forward with details of our own and other reference sites.