Looks like like a great system. Although if you really want to have video in and a tv tuner. You might want to consider getting a dedicated PCI card (Hauppauge PVR-250) for the video in and just stick with a 9800 Pro(Sapphire Radeon 9800 Pro) for your video card. I heard that the PVR-250 is great for video in and you may get better results.
When you said 17 inch flat screen, did you mean a flat panel LCD or Flat screen CRT monitor? If you meant an LCD, you should check out this thread at another forum. If you mean a CRT, I would suggest the NEC FE750. I have an NEC FP950 (the 19in. version) and it's great. The only thing that may bother you is that there are 2 very fine lines that run horizontally on the screen. It's because the monitor uses Sony's Trinitron aperture grill tube. The lines are only noticeable on bright backgrounds. It's just a small trade-off considering that Sony's Trinitron tube producs a very sharp picture.
You're asking for advice, so I'll give you mine: Athlon64 for gaming. Save some money on the mobo, too. :-o If you're set on Intel, completely disregard this post. I'm not trying to start anything.