Cheap, quiet PSU for SLI setup?

Thanks for the suggestions. System is 3570k @ 4.5GHz, Asrock Extreme 4, GTX 690. I'm in the UK so I know that makes pricing awkward.

Based on your brand suggestions I found a Corsair CX750, OCZ ZS 750w and Silverstone SST-ST70F-ES, all exactly the same price. Currently have the 550w of the Silverstone PSU and pretty happy with it, thinking to go with that again. Slightly apprehensive about the Corsair one as from looking around it seems people are having alot of them with coil whine, and I've found Corsairs support to be terrible.

Any suggestions?