Finally purchased & setup the new HTPC, was a couple of delays along the way, but setup is pretty close to what I had planned in my previous post.
Case - kustompcs.co.uk:
Antec ISK 300-150 Mini-ITC
Motherboard - kustompcs.co.uk:
ASUS AT5IONT-I Atom D525
£135 + £24 Shipping
Fans - quietpc.com:
2x Noctua NF-R8
€30 + €4 Shipping
elara.ie: Kingston 1GB PC8500 DD3 SODIMM
€24 + €8 Shipping
misco.ie: Kingston 2GB PC8500 DD3 SODIMM
€45 + €3 Shipping
Case same as the low-power always-on box I have, except went from 65W power brick to 150W internal PSU with fan (Motherboard needed 90W max, and only option for power brick would have been picoPSU which I could still go for if wished).
PSU fan is thankfully as quiet as the Noctua fans, so no need to go for picuPSU.
As previously mentioned, I found the Noctua fans excellent, so went for another pair of the NF-R8s.
Motherboard was the thing I'd been waiting for. Soon as I heard about ION2, been waiting for a suitable board to come out.
Newer generation Atom uses less power, so although I haven't taken any measurements yet, I can only assume the box uses 25W or less.
Using Fedora 13 again for XBMC (SVN) with MPlayer (SVN) for playback, which is the best player I've encountered for VDPAU playback.
Performance is excellent all round, smooth menu navigation and transitions, and no problem with playback.
I did test Debian Squeeze (with an ION1 box), and noticed massive problems.
Lirc and menu navigation was sluggish and juddery.
Outputting video & audio over HDMI from the HTPC to my amp.
The box is near-silent, faint fan noise can only be heard from it when 1m away from it, as I generally sit 3-4m from it, don't hear a thing. It stays reasonably cool, typically at ~40°C.
I'll post up my configs & scripts used soon, and hopefully get some pics up by the weekend.