Build a Custom Social Network

Need someone with experience building custom social networks with php. Site should be scalable and feature common tools a traditional social network would have such as add friends, photos, videos, wall posts, privacy settings, activity points etc. Need a special component that allows moderators to monitor conversations by members and flag offensive words and conversations between under age members based on loaded keywords. Ability to alert moderators via email SMS messages would be ideal as well. The editor is able to preview the conversation by clicking on a link next to the returned item. Should he/she find any signs of violation of the site policy or any other applicable infringements, the editor can issue a warning that will be sent to both parties of the given conversation. Editors are also able to ban users for repeated or severe violations by pressing the appropriate key. The component allows several editors to work simultaneously and notifies users of warnings issued to them. We are not interested in cheap 3rd scripts. Please send us samples and screen shots of any custom social networks you have built from scratch and proposed solution for conversion monitor.