Helpdesk / ticketing / support system (ready)

Hi, We are looking for someone who has ALREADY developed a help desk script which has these features. 1. live chat applet (desktop version optional / common IM support optional) 2. ticketing system 3. knowledge base / faq system. The workflow should be something like this: 1. user enters chat / user submits question via contact form / user submits question via email 2a. support answers chat and pulls answers from knowledge base if available. 2b. support receives email on ticketing system and replies by pulling up answers from knowledge base. 3. if there is no answer, support can submit it into knowledgebase. 4. knowledge base has to allow image uploading / embedding so screenshots can be provided to help user. 5. tagging should be allowed for easy finding of answers related to keywords. Please post your demo url / login / password for us to review.