I just checked that dazzle site, and it is essentially a card that will convert your signal to digital. It is only $169 so I would be careful. I'm not sure what kind of quality you will get or compatability. I would do some serious research on that before I dropped any cash on it.
Story: A couple of years ago Iomega had this thing called a buzz card for like $200 that converted video to digital. I bought it to go with my new G3 tower. Turns out the buzz wasn't very good and not even compatible with my hardware, so I had to go and buy a Pinnacle Systems video card that cost $1000. Moral? Do your research.