live support chat software

I am looking to purchase a ready made, turn key solution to start a hosted live support chat service. Similar to: [login to view URL] [login to view URL] The code should be in php/mysql/ajax. I have seen many solutions in the past, but I am looking for the right solution. I do not need a windows client. I'm just looking to buy the best "cloud" solution. If you have a solution, place a bid, and send me details. Again, I am NOT looking for a custom solution to be built from scratch. I don't have time to work with a development team on such a project.