I'm in process of building a gaming pc and I would like to know if Athlon x4 760k would bottleneck two GTX 660 in SLI ?
I'm new to this so don't get to mean
Like the two above said, the Athlon X4 760K won't work for you, and there is really nothing better to upgrade to.
If you want to spend the money on a new computer, definitely get an Intel i5. Intel i5's can keep up with even the best GPUs out there, and all at a reasonable price.