Back in 2007 LXF did a feature on the ULB. I was told it didn't sell too well, making LXF having no intention to repeat the performance. So I thought, let's give it a go, starting with the one market Linux has a very strong presence: servers. Prices in Euro, from a Dutch webshop:
Case: Procase IPC-C3F
(6x 5,25" extern, 2x 3,5" extern, 1x 3,5" intern) 309.00
PSU: Procase PIZ1038-EPS
(650 Watt) 699.00
mainboard: Asus Z8NR-D12
(Retail, DUAL, RAID, Gb-LAN, VGA, SSI EEB) 389.00
processor: Intel® Xeon® E5520
(Boxed, FC-LGA4, "Bloomfield", x2) 429.00 each
Cooling: Cogage MST-140
(x2) 34.99 each
RAM: Kingston ValueRAM 4 GB
ECC Registered DDR3-1333 (Retail, KVR1333D3D4R9S/4G, x12) 149.90 each
system-disk: OCZ OCZSSD2-1ONX32G
storage-disks: Western Digital WD20EARS
(2TB, x6) 129.90 each
cardreader: Shuttle 22in1 Cardreader
misc: standard 2.5"=>3.5"Adapter (2,5" in 3,5" bay) for SSD 4.99
The total would be some 5,020 Euro. Not cheap, but then: servers aren't cheap and this wasn't on a budget
The OCZ 32 GB SSD disk is screamingly fast (125 MB/s read, 70 MB/s write) so the machine will be very responsive. The only thing keeping it from the psychological sub-minute boot is the OS itself
The storage disks are 2 TB in a RAID 5 array and give you 10 TB of redundant storage. The 4 GB DDR3 RAM sticks are expensive, especially when you put in 12!
However, servers thrive in the presence of RAM and the board supports 48 GB. If you want to save, use 2 GB sticks instead. That still makes an impressive 24 GB and saves you a massive 816 Euro (Kingston KVR1333D3D8R9S/2G, 81.90 a piece).
The mainboard offers 3 LAN ports, 1 Gbit each, and has a Dual Xeon proc on board. That is some serious computing power. Because of this, it's not an ATX board, but SSI-EEB and the case should reflect that. The housing comes w/o PSU and the 699 Euro PSU has triple redundancy. For extra security you may want to add a UPS to at least one mains input. Enermax do 19" rackmount UPS's, but APC has a reputation to loose here
The coolers aren't quiet at 33.5 dB(A), but air displacement is a whooping 160,9 m³/h (or 94,7 cfm) to keep things cool in the hot server room. In comparison, avarage desktop coolers are in the 20-60 m³/h range...
The card-reader is there as there wasn't room for a CD/DVD drive and you'd have to install Linux on it
A simple SDHC card serves as installation medium and then functions as a backup for the system-disk.