Will a 660w GOLD PSU be enough for GTX 660ti SLI?

Hello there, I'm planning on a 660 ti SLI build.

I've read in various sites that the typical recommended psu for an SLI setup is 750W.

However, can a 660W GOLD PSU make the cut? Specifically, I'm talking about the Seasonic X660 Gold PSU. I hear those power supplies (the X Series) are actually more powerful than stated. I've read somewhere that even the 560w can draw 700 watts while maintaining high efficiency.

So will the X660w be enough for SLI?

My CPU will be a 3570k, and the mobo will be a Gigabyte Z77x UD3H. I won't be doing any overclocking, since I really have no idea there. I'll just overclock the CPU in the long run once I gain enough experience. Regarding the GPU's I won't overclock them since there's practically no point since it's already in SLI.

If that's not enough, I can buy the Seasonic M12II 750w Bronze PSU, just to feel a little safer.

Thanks a lot guys.