I have a home-built Shuttle K45 with the following components:
Shuttle K45 barebones PC
Intel 2.53 ghz Core2 Duo CPU
2 gb Super Talent DDR2/667 PC5300 Ram
2 1tb WD WD10EACS Hard Drives
1 Shuttle ICE Genie CPU Cooler (near silent operation)
MS Windows Home Server software
Spare SATA Power and Data connector
Although I dont encode/transcode that much, even with 2 gigs of RAM, this machine hasnt so much as coughed in over 2 years.
I run playon server along with PS3 Media...