Chat-name forms and Suffixes with Validation...

Hi Everyone, I'm making a form that takes the chat name user enters and combines it with the chat suffix. Does anyone have a list of all the available chat clients out there? So far I have, AIM, .mac, iChat. What's the easiest way to combine them with the actual name? JoeTreeman6.mac for example. But how do I do it if it's something like SarahPoley69 on AIM? Does it even have a suffix? What about checking to see if they are on line? Not signed into the site but actually on line yaking away in cyberspace somewhere. And is it possible to verify a chat-names authenticity? Like does it really exist? Or if it's one of those sex bots that bombards the AIM chat rooms with 18/f/Web Cam crap? Thanks in advance. Sincerely, Ryan Munevar