DrDoc - 4:32 pm on Oct 9, 2013 (gmt 0)
You are looking for a commercial product. I am not well versed in which ones are out there, their pros and cons, or which feature sets may be available.
As long as you are prepared to pay for the product and will have a dedicated server available, you should be able to find something.
Chat services put a lot of strain on the server and aren't as popular as they once were, so you may need to do some digging.
In any case, we do not have a suitable subforum for this particular need.