Any chatroom recommendations?

[FTDave]

Hi.
I'm using phpmychat right now.
It is integrated with vbulletin thanks to some hard working coders on this site.

My problem...........
I used to have 40-50 chatters at one time.
Now I'm lucky to have 4-5.
They really don't like the chatroom.

Does anyone know of a chatroom that can be integrated with vbulletin?

Requirements:
1. Must be fast.
2. Not too expensive.
3. Be able to integrate with vbulletin.
4. Most important thing. All coding must be on my server. Independent to any other servers. My site is too large to depend on someone else's site for my chatroom.

Thanks.
Dave.