I'm really quite happy with MythTV at this point, except that the ITX system just isn't quite cutting it as the machine to go into the family room media center. Mostly because it only has one PCI slot. If the ivtv driver could support both input and output on the PVR-350 at the same time, it'd be nearly right... but...
I have an unused ATI Radeon 7500 All-In-Wonder card. The video input and tuner sound like a lost cause for MythTV, but with the GATOS ati.2 driver the card reportedly works fine for output including NTSC. The card also came with a UHF remote control that would adequately replace our "dependency" on the Sony DirecTV UHF remote we are using today. So, this feels like a good output and remote control support card for the media center frontend. Thus, we need an AGP slot.
I have a Hauppauge Bt878 capture card in the ham shack machine that is unused since it doesn't seem to work well in the dual Celeron motherboard. With an available PCI slot, MythTV should be able to use it just fine if there's enough CPU to compress in software.
I also have a 4dwave NX audio card with optical S/PDIF output if I have a PCI slot and inadequate sound output support on the motherboard.
So, I ordered parts for a new machine from newegg.com. My first order from them, but others seem to think they're OK. The components I ordered will make a fairly fast Micro ATX system. As long as it's not too loud, it should work out fine.
Asus A7N266-VM motherboard. This board is cheap, has what I need, and apparently works well under Linux.
Athenatech Micro ATX Case w/200W Supply, A100BB.
AMD Athlon XP 2400+, the fastest 266 FSB boxed Athlon in stock.
512Mb PC-2100 DDR266 RAM
So, hopefully, by the end of the week I'll have a more immediately suitable box to run MythTV on...