At £344.58 one might be better off buying several smaller power supplies, name brand 500W and 550W power supplies seem to cost about £40 or £50 or so so one can have
7 for the same outlay in cash.
My first rig used an expensive 1200W PSU... which lasted about 18 months.
Subsequently, I have used multiples of 500W and 550W power supplies without any failures. I have a spare 550W Antec standing by for when one does go down, and have still spent less cash than if I had bought big PSUs.
Takes up lots of space, though.
Nice idea with the redundancy !
The space isn't that much of an issue - my rigs are in the attic where there is plenty of room.
Picture a motherboard with 4 5780s, some attached using PCIe x1-x16 connectors, powered by 2 550W power supplies, on a shelf. Add a water loop for cooling. A bit... untidy.
Between 3 such rigs I get more hot water than I need. If I thought GPU mining was going to be worth doing into the far future, I might consider growing tomatoes in a heated glasshouse.