Re: Graphics/Video advice needed
Wow 300 watts?!?! Whoa that thing is tiny. Get a 450 watt power supply instead. Your TV tuner card should be just fine as the video card is a totally separate system. You know how you're using the nvidia geforce 6100 integrated graphics? Well, instead of plugging the monitor cable to the back of the motherboard, you're just plugging it in to your new higher performance video card. You should be totally fine with this nice upgrade.
I have the exact same setup as you with a TV card at the bottom of my case and a video card right above it. Works great. You can still watch TV as usual and the added benefit of a much better video card.
*Fact: Microsoft Window's Blue Screen of Death vs Computerforums.org's White Screen of Death. Which is worse?