First things first, I would not bother with the snazzy all-in-one LG monitors. All they are is an LG monitor with an NComputing XD2 access device built in to it...and they are expensive.
In the interest of saving bundles of money, I would suggest you go for an NComputing X550 5-user kit (RRP £330.00 = £66/user), 5 standard tft monitors (about £100/each for a TFT) and a well spec'd PC (say about £600). You get 5 NComputing XD2 access devices in the NComputing X550 5-user kit along with the 5 port card and vspace virtualisation software. It doesn't matter what brand the TFT's are. The XD2 access devices have standard VESA fixings so they can be mounted to the back of the TFT. Although if you're thinking of mounting the XD2 access device to the back of the TFT, you will need a TFT that has a stand that does not use the VESA fixings on the TFT.
The NComputing X550 works perfectly well with Windows MultiPoint Server 2010...can't really expand on that I'm afraid.
It would be difficult to say what advantages NComputing can bring over a system with an ATI 6 port Eyefinity card with 6 monitors, because it's a bit like comparing apples with pears. As far as I'm aware an ATI 6 port Eyefinity card with 6 monitors would simply provide the PC user the ability to use 6 different monitors at the same time...where as NComputing is all about sharing the computing capability of one PC to multiple users. To put it another way, the NComputing X550 will extend your single user PC to a multiple user PC...you can have up to 10 additional users from one PC (2 x NComputing X550 5-user kits in one PC).
With regards to energy, NComputing devices range from 1w to 5w's of power, depending on which NComputing product you're using. A typical PC would use somewhere between 100w to 150w's of power. So you can radically reduce your power consumption...and radically reduce your electricity bill as well...and it will also help you sleep at night because you're massively reducing your carbon footprint as well...saving money, saving energy, saving the planet (i'll get my coat!).