Much better PSU but you have gone a bit overboard! The 750W Supernova B2 would have been more than enough. That 660 is very underpowered for such a high end CPU but I assume you'll be changing it eventually?
If they won't fit the PSU for you Cyberpower will do this for £493
Remember, the eBay PC doesn't come with Windows either so that will be another £70-80
Case: Cooler Master HAF 912 Mid-Tower Gaming Case (Black Colour)
Extra Case Fan Upgrade: Default Case Fan
CPU: INTEL® Core™ i5-4590 Quad Core 3.30 GHz 6MB Cache LGA1150 + HD Grapics
Cooling Fan: INTEL Socket LGA 1155 Standard CPU Cooler
Motherboard: Gigabyte Z97-HD3 INTEL Z97 Chipset, ATX Mainboard w/ 4 RAM slots, 7.1 HD Audio, HDMI, GbLAN, USB 3.0, SATA-III, 1x Gen2 PCIe x16, 1x Gen2 PCIe x4, 2x PCIe x 1 & 2x PCI
Memory: 8GB (2x4GB) DDR3/1866mhz Dual Channel Memory (Kingston HyperX Fury Blue w/Heat Spreader)
Video Card: Integrated onboard Graphic
Power Supply Upgrade: 600 Watts Power Supplies (Corsair 600 Watts CX600M Modular Gaming Power Supply, 80+)
Hard Drive: 1TB SATA-III 6.0Gb/s Cache 7200RPM Hard Drive (Single Hard Drive)
Optical Drive: 24X Double Layer Dual Format DVD±R/±RW + CD-R/RW DRIVE. (BLACK Colour)
Sound: HIGH DEFINITION ON-BOARD 7.1 AUDIO
Network: ONBOARD 10/1000 NETWORK CARD
Operating System: NONE
Warranty Service: DESKTOP STANDARD WARRANTY: 3 Year Labour, 2 Year Parts, 1 Month Collect and Return plus Life-Time Technical Support