3 Way SLI with Rosewill PSU

It should work because the PSU has enough power and enough connectors. But I wouldn't trust that brand of PSU. One I would steer clear of. Instead would buy one of these.
Not Modular- http://www.newegg.com/Product/Product.aspx?Item=N82E16817703028
Modular- http://www.newegg.com/Product/Product.aspx?Item=N82E16817341045
There is a reason that PSU is so much cheaper than the other PSU. If I was buying one I would want the second of these two simply due to it being modular, but you have managed without it so far.

You should have room to overclock at 1000w (if that PSU can actually handle it).

Just wondering what you mean saves you power? The GPU use most of the power you may save 20w or less switching to a ivy bridge processor.