Remote access chat software

Hello, need a remote chat software so that when individuals come across my site they can chat with an online representative. The chat window must be able to be branded with different graphics and logo. The software must be 100% unique, and if you already coded one thats fine but you have to have made it. Budget is $60, looking for someone how has already done something similar. Make sure to show a demo if you did. Will also need to provide a quick installation guide and user manual for this. This needs to bes tested as well and the system requirements must be given as well. Thanks and looking forward to working with you.