Experienced Website Designer Required for New Project

I need to have a new B2B website created. The site will need to have Social Networking and appropriate PPH, LinkedIn, type functionality. I will need the successful applicant be familiar social media and with the various features on these sites and their underlying technology in order to propose which specific functionality to include on the new site.

I will also need to have a simple Content Management System, which allows new pages and content to be added, and structural changes made to the site by non-technical members of staff. A DRUPAL based site may meet the requirement, but I'm open to suggestions.

A full brief will be given to the successful applicant.