if we do end up using IRC server there will be no free access to it, only from a java applet in our site and with limited funciality for the chatter, so it should be safe enough

We had good experience with Badpupy's own IRC server and a $25 IRC applet in the past- but we want more chat functions now

The problem with those java applets is that the members need to click to authorize their use, and that scare some of them. Flash onthe other hand just load up to the browser with no extra steps