Lenovo E50 Desktop PC
Intel Pentium Quad Core J2900
Windows 8.1 with Bing
I basically stumbled across this when I was looking for a really low power consumption PC, searched based on the 10W J2900 CPU and bingo. I'll add some RAM (So-DIMM cheaper than std) and an SSD and this will be nearly as fast as my i3 540 (73W) and save 63W - my PC is on alot so will save a couple of quid a month too!
Though not detailed on the Ebuyer site the Lenovo £30 cashback deal is available on this but you will need to be quick, ends at the New Year!
Price is £149.99 with possible cash back of £30