Is this power supply compatible with my mobo?

Yes, that power supply is compatible with the Mobo and a Single 560Ti But if you want to add another 560Ti later on this is going to run short. You might end up with random restarts under load.
My suggestion is go for a PSU that is 80+ 700-900Watts. With dual rails or more
Something like this is a lot better
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371051
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182067