Install & modify an OS Q&A forum on our server

The developer should: 1/ Install & configure a Open Source Q&A software (Stack Overflow clone) on our own virtual server (root access & full rights available). Choose & suggest the right software - a PHP / MySQL system is preferred over a Python or similar solution. 2/ Apply custom template to the system (custom CSS & some minor HTML changes). Design in PSD provided. 3/ Modify the user profile page in the system to enable: a) extended custom profile info (custom text fields & links to own website, facebook profile etc.) b) one additional user level - "professional user", enabled by the superadmin, to distinguish general public & professionals c) gallery & image uploads in the profile page, organized in albums (Uploadify & jQuery lightbox for picture viewing - should also enable simple YouTube video embeds) d) Facebook login (if the system does not already provide this)