THIS IS WHERE I GET GIDDY!!
You can build a computer then download an O/S called MythBuntu. It's basically a free version of Windows Media player except it's Linux-based... but severely user friendly.
The only thing you'd need to do is get a controller / Infared receiver for your PC.
My phone (iPhone) has an app that lets me control MythBuntu from it. So if you have an iPhone, you can do that.
MythBuntu boots up right into the 'Myth' part, which is Windows Media Center on crack. Much better put together IMO.
Just get together a POS computer and you should be fine.
Or I'll sell you mine for $500 //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif