Hi, this looks very interesting!
I'd like to try to get this running with a standard Ethernet shield and widely-available low-cost relay boards.
Also, you may want to consider the start-up / reset issue to assure no relays can momentarily click on. Some info here: http://arduino-info.wikispaces.com/ArduinoPower#4-8
I'd want to use optically-isolated relay boards like these, which have 2,4 and 8 relay versions: http://goo.gl/xeV7l
DISCLAIMER: Mentioned stuff from my own shop... (which is what I know best 
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