We don't know much about in-site search tools, offhand the only one besides Google that I know of and have heard good things about is IndexTank, so you might look into that.
We've started using SnapEngage for our own live chat (see that button over there? --> :^), so you might look into that for your site; it uses any Google Talk-compatible IM client app for your agents' end, with customers using a chat window inside your site of course. We used to use LivePerson but weren't thrilled with the proprietary client app our agents had to use for that, so we looked for something better and think we've found it.
