Alright, here is my opinion on using any gaming chat for shows.
Teamspeak: Great program that provides realtime communication as well as amazing Audio quality, including the option for using 3D audio. The only down side is setting up a teamspeak can be time consuming and tedious if you want to make it as secure as possible.
Ventrillo: another chat program. I wouldn't recommend it, very low audio Quality.
Skype: don't even try, having any more then 3 people in a Skype chat can cause headaches.
Discord: This is a new program that is picking up steam. It's very similar to Teamspeak but free.