<< When you get a multimedia video card, you will ALWAYS lose gaming power. That's just how they make the cards. >>
Not always, the multimedia features are generally handled independantly of the GPU. Unless you are trying to capture video while gaming, all things being equally, the performance will be the same. My AIW Radeon performs identically the same as a Radeon 32 DDR retail. A Radeon AIW 8500dv and AIW 7500 will not perform to Radeon 8500 performance levels because the core/memory are clocked below retail speeds. Extreme cooling may get you retail clockspeeds, probably more likely with the AIW 7500 because of the heat generated by the 8500dv's tuner chip though, but why risk an expensive AIW card for a few fps?
Win2k is definately adequate for gaming, the drivers for most cards are very mature now and equal to and sometimes exceeding win9x performance. If you are getting a capture card, you want to use NTFS if you're working with large files anyway, that means XP ot 2K. Nothing to worry about there.
The TV wonder isn't based on the Rage Theater chip, you wont get the same functionality or compatability of the AIW cards, but it may work fine for what you want, and you can just upgrade your video card down the road. I'd do some research first and check out the hauppage cards and ask around.