So it is sounding like there is no easy answer here, and I can't just use the PS3. With what I have today adding a media center extender and network over powerline is probably my cheapest option. I assume the harmony remote can be used to control the xbox/media center extender. I'm thinking the xbox will start to drop in price soon, since the new one is on its way to release.
The PC in the office would be fine doing double duty as a media center. If I were to build one I found some things online where you can do it for ~$500 vs. the 1800 mentioned here, albeit with less storage I'm sure.
