Ah, I'm a little late to the party here.
killem2, you'll actually LOVE that gigabyte board from what I hear. This is actually a really good setup and is quite similar to the one I've built for the Techgage "beefy" HTPC, which is designed to allow a bit of gaming along with the HTPC functions. Main difference was that I dropped in an ATI 5570 to give a little grunt to the games.
I'm personally a fan of the passive, and I'm sorry I didn't get around to this a little faster because your wife might have liked my suggestion - which emphasizes silence over speed. Any NVidia GPU can use VDPAU on Linux, and XBMCLive is a GREAT home theater OS for free. So ION boards become PERFECT for a 720p setup in particular, and would've brought your price down by about $80 from your setup above, and also don't have annoying fan noise.
That being said, I don't think you'll be disappointed in this setup.
There's a lot to love here!