To go with the video projector, I'm thinking of building a HTPC box running Linux/MythTV. The thing I can't figure out, not having a desktop machine to properly test things on, is what hardware I need for the job. Comments would be welcome..

What I'm thinking is a system with a big hard disk, DVB receiver card and a DVD/CD-RW drive. I want to be able to record and watch TV shows as well as DVD movies, and being able to archive stuff in MPEG-4 format to CD would not hurt. It would also be home to our music collection, which I'm encoding from CDs to Vorbis. Being able to play a game now and then would be a bonus, but since the system is going to be running Linux anyway, I do not expect to see a lot of games on it.

To do this, the system must have enough CPU power to play back DVD, DVB and/or MPEG4 content while recording a DVB stream at the same time. It must also be able to output 5.1 audio in analog format, due to my current AV receiver not having built-in AC3 decoding. On the other hand, since the picture output will be to a video projector, I do not need S-video TV out signal, standard VGA is better. At least one PCI slot is a must, even if everything is integrated, because of the DVB card.

The cheapest, and at the same time well performing option looks to be an AMD AthlonXP/Duron with an NForce2 IGP MicroATX motherboard. However, I'm worried about the power and heat output of those systems, as obviously I want the system to be quiet (passive heatsinks would be optimal).

An EPIA MII-10000 should be able to (barely?) do this as well, but it probably won't have any CPU to spare, which worries me (have I understood everything? Am I overlooking some part of the requirements?). It would, on the other hand, probably be quite a bit cooler, although in standard setup that system also has a CPU fan.

Pentium 4 is a fallback choice - most expensive, but in lower frequencies puts out less heat than Athlon. Pentium M would be ideal, except it's even more expensive, and anyway the only desktop motherboard I've located for it does not seem to be sold by anyone, anywhere. I don't want to wait for the rumored Pentium M desktop edition, either. Anyway, there is no chipset as attractive as NForce2 for Intel processors.

As for case, I'm thinking DIGN HV5 - expensive, but really cool (pictured above). Even Sanna thought it would look OK. :) This case would take pretty much any system, being able to house most ATX motherboards. Being all-aluminum, it would probably permit some advanced heatpipe solutions for replacing at least the fans needed by an EPIA system. In any case, the common SFF boxes are out of the question - I do not want this system to look like a computer.