Looking at maybe a linux solution for my home theater. I don't need live tv ability just playback from MKV files mostly. I've acquired a large collection of HD rips in mkv format but would like to separate them from my regular pc and set up a front end for the home theater. Maybe they could be stored on usb external drive? My display is a mitsubishi HD1000U so even my 1080p rips will be dropped down to 1080i by the projector, or I can use the box to scale it down first depending on what's easiest. Basically I'd like a movie store in a box. Any suggestions? Would I be better off with windows? Can linux handle 1080p and how much hardware do you need for it?

Any display card can handle 1080p these days. You'll get DVI out, which can be turned into HDMI using a simple dongle or cable. However, if your projector doesn't have HDMI in, you'll need to look carefully for a solution that does DVI or VGA to component -- many solutions don't work that well IMO.

On the front-end part, I'm still struggling with that same question (see different thread), and the suggestions I've gotten so far include installing MythFrontEnd on the box that drives the projector, and the Myth back-end on the box that actually contains all the media. I suppose you could install both on a linux box, and make that box contain the media, if you want, and export the media back to your PC using a network share.

How about specs on the pc itself? processor, ram, mobo?

I would go with 2 GB of RAM. I would use a mobo with built-in graphics for cost savings -- if you can find one with the right output for your AVR/TV, that'd be best (HDMI/DVI or VGA -- no mobo has component that I know of). I like the Core 2 Duo, and they've just come out with the -50 series with faster FSB, which matches to the G33 chip set -- don't know if you can get that with HDMI, though. Might need a separate graphics card for that, in which case build-in video is just an unnecessary cost. Get the fastestC2D 6x50 you can justify.

If you can find a mobo with built-in digital sound out, that'd be good, too, as it saves the cost of a separate sound card. However, as I don't yet have a working Myth set-up, I can't give you more specific advice than that.