Content website based on Drupal

I need a website to be programmed in Drupal and deployed afterwards. It should be based on Drupal. All designs will be provided as psd file. These are the specs (pls see attached design files for further reference): GENERAL ELEMENTS OF THE SITE - Logo/header area - Navigation (see attachment) - admin must be able to edit, add and remove navigation elements - Footer with links reflecting the navigation plus some more text elements HOMEPAGE - Latest news (teasers for manually entered news articles) - Text/picture boxes below Latest News section - Contact box on the right - Twitter stream with tweets and dates from a Twitter user account TEXT PAGE - Various headline/text formats - same column on right-hand as on homepage OTHER SPECIFICATIONS - Bi-lingual - German and English version (see language selection in upper right-hand corner of designs); initially only the German version will be deployed - All text and pictures must be editable by the admin in the site's backend system - The site must meet at least some standard SEO requirements: Usage of H1, H2, etc. for headlines, editable Title, Description, Keywords and URL for each page, editable alt txt for pictures