Picking a chat client

[VodkaFish]

I've seen things on this site for:
Digichat
Sigmachat
and I saw someone mention they had Chatblazer integrated.

I'm not sure if I missed any others though

What I'm looking for:
- Integration with vb
- Censoring of words
- Ability to only allow certain usergroups access
- Ability to have certain usergroups be defined as chat moderators

What I'd like:
- Instant messaging
- Direct file transfers (not using my bandwidth)

I spoke to someone briefly from Digichat, but I was still unsure about a thing or two, namely if IM is available on their basic pro server package. Also, I don't know if I'd get anything other then the pro server, at least to start as Digichat is on the pricey side and I have no idea if this will take off with my users, as much as they request it.

Sigmachat doesn't look quite as nice, but the features could be comparable. I hate using anything relying on someone else's servers though, so that's a big turn-off.

Am I missing any? Has anyone tried more then one? Does one "fit" better into your site then another? Any control advantages or perhaps money advantages in any?