Well, if someone is interested in a chat room for his radio show like me than I became and expert in this field. Here are my experience with finding the best one for my radio station.
1 - First I needed a chat that can be seen in mobile (all versions) so I narrowed down the search for html5 chat room that look good on both mobile and pc.
2 - I needed a custom design, I needed my background to be black or transparent. This was very hard to find.
3 - I do not like to install the chat in my server as this is high cpu and resource consumer. So I need a chat service.
4 - Lastly, I needed the ability to add youtube videos.
I have checked several chats and only 2 met my needs, RumbleTalk and Envolv.
I choose RumbleTalk finally as it can be integrated into my page and not only as toolbar.
Since I could not find answers in this forum, than I hope this overview will help someone.