I'm trying to get all my ducks in a row before buying XenForo. One of those ducks is chat software. I've heard good things about Arrowchat. I only have one concern - I'd like a member to be able to sort the list of people he sees online, or only see people with certain attributes. Is that possible with arrow chat or another program you are aware of? I have no programming skills.
You can set Arrowchat to display everyone who is online or just friends (those who you follow). Arrowchat can also be setup so that only certain usergroups can access it rather than everyone (something which I've done on my site).
Cometchat does not have usergroup permissions. It loads for all users and therefor adds such load to your server. It does allow you to hide the footer bar from fully loading with a conditional. All your users will be able to access chat through the webapp / cometchat directory.
Cometchat works through port 80 instead of directly to a chat protocol.
Cometchat is riddled with bugs.
Are you saying you think they'll make the mods I mentioned for free, or just that they offer customization as a service? I seem to remember arrowchat telling me what I ask for is possible, but they won't be able to help me with it.