update Nov 7th 2015
For reference, this is the list of components that I ordered in 2011. Some of these parts are more difficult to come by however by checking the specs you get a good idea of what I did to achieve the low-power and low-cost of the build. A good starting point now is to look at the successors of mainboard, CPU and memory.
The only thing you might need to add is the storage device. As I already have an iSCSI capable NAS, my new QNAP TVS-871, this is all I need:
3x OEM Networkcable CAT5e Blue 0.5 mtr (artnr. 337736)
3x OEM Networkcable CAT5e Yellow 0.5 mtr (artnr. 337730)
3x OEM Networkcable CAT5e Green 0.5 mtr (artnr. 337727)
3x Intel PRO/1000 PT Dual Port Server Adapter (artnr. 37894 see note)
3x Case Antec ISK 300-150 (artnr. 257466)
3x Intel Core i3-2100T Processor (artnr. 392591)
6x Transcend TS1GLK64V3H 8Gb (artnr. 481691)
3x Intel Desktop Board DQ67EP Executive Series (artnr. 396345)
3x NETGEAR ProSafe Plus GS105E 5-port Gigabit Ethernet Switch (artnr. 243035)
This hardware will set you back around €1500,- which fits nicely in my low-cost budget for the project. The only change for the new build is larger memory modules as outlined in RED which provide 16Gb for each node and I replaced two of the switches for a provider-grade model which handles all the VLANning.
Note: make sure you buy the Intel PRO/1000 PT Dual Port Server Adapter, which has the 82571EB chipset, as the ‘regular’ Dual Port adapter (82571GB) does not have the iscsi firmware menu available. You can flash the new firmware and it shows the CTRL-D main menu but that’s it. No access to the iscsi settings.
(Thx Niels for finding out the hard way 🙂 )