I've been recommending the $40 (CompUSA) I/O Magic PC PVR card http://www.iomagic.com/support/video...CPVR/index.htm
It has very good quality TV, s-video and composite in, and comes with VCR type software. Don't believe the documentation that says the s-video and composite in don't work -- they do. As for XP, I don't know. I guess you could either call the company (but whether they'll reliably know is another matter) or try it yourself and return it if it doesn't work.
I think it's a good idea to have the TV tuner function separate from the video card because you can upgrade either without major disruptions to your system. And with the video card you already have, why get a lesser one? By the way, I'm using it with a GeForce2
You can do a search here and get more info on it.