"If you are going to use your rig mostly for gaming, 1600 is more than enough.
You won't really see or notice real world gaming difference between 1600 and 2400 with a 770 GPU in gaming.
Unless you are going to use it for benchmarking purposes, then you will notice the differences in numbers.
If you are going to use the integrated graphics, then maybe you'll notice 1-3% difference.
I would suggest to focus on the size of the RAM and/or the CL instead of the frequency for gaming. "