the HUSH PC looks nice... sort of what I was looking for... but the price is little too steep for me...
for a less expensive alternative to the hush pc, check out the via epia based serener gd-L01 at logicsupply.com, in the "fanless systems" section. it has room for one pci card, plus a firewire port, 4 usb 2.0 ports, and onboard sata raid0. using external hdd enclosures with esata connections, it is possible to rig up an external raid0 volume, currently up to 1 terabyte. very nice looks and function... fits right in with other stereo components.
i use this with an m-audio firewire transport and an external dac. i use a samsung notebook (2.5") hard drive for the system drive, mounted in the case on soborthane pads. for music storage, i use a 250gb samsung sata hard drive in an external enclosure, connected via esata. it's taken me a several years to arrive at this setup, and it's awesome...
you can put together a great system, with 2.5" system hard drive and 250-500gb esata external hard drive, for under $1000. i would highly recommend soft-mounting a 2.5" hdd inside to minimize noise levels from hard drive seeking and also to reduce heat build-up inside the case. from my experience with a 3.5" seagate hard disk installed inside the case, i would say it runs too hot (mid - high 50's C, occasionally peaking over 60!). by comparison, the 2.5" runs in the high 30's or low 40's, never reaching over 44 or 45 under the heaviest loads. it has the added benefit of being virtually silent.
another recommendation, if you have a laptop and windows xp pro, use "remote desktop" to connect to your audio pc and control foobar2000 remotely.