Does this chat bot interact through a web interface, or does it use AIM's oscar protocol, or what?
EDIT: Sorry, I guess the subject of this thread explains that.
You should take a look at the Apache web server and PHP. PHP is an excellent scripting language perfect for dynamic web pages. I'm sure you could design an interface that actively interacts with your chat bot. If you use another host but you still want PHP, then just make sure that you will have access to PHP on their servers.
There are two web hosts that I've looked into for a while; IPOWER
and Web Host Freaks
. I currently use IPOWER for their domain names and I run my own server, but they're primary service is web hosting. Web Host Freaks is a pretty cheap host that uses Red Hat servers. They offer PHP on all of their plans.