SEO module on top of excisting website build in Drupal

Hi all We need to have a SEO module for Drupal installed on top of our web-site. We have 5 different kind of templates for articles and right now we have 400 articles. See more on: [login to view URL] We need to be able to do the following: 1. Change article names into H1 tags instead of H2. 2. Add Meta descriptions 3. Check and correct W3C validity 4. Internal linking 5. Noindex metatags on some pages 6. [login to view URL] 7. Did we forget something? I look forward to hear from you.