Um...sirquack. You don't need a PVR card. If I understand correctly, you are meaning a Personal Video Recorder card?
An HDTV card does that one and the same.
Windows XP Media Center has an integrated TV tuner program which can automatically record TV shows with a TV guide and has integrated DVD software as well as a music playback system. You're going to want that as the operating system instead of numerous other programs.
Also, you can get a program such as Norton Ghost to automatically back up your most important data onto a dedicated backup drive. That's what I do, and I can still use the extra space on the backup drive for other things too.
Hard drives don't just die all of the sudden anymore, they are becoming more and more reliable. They are much more likely to die in high stress environments, such as a server, which is why servers use RAID much more than desktops do.