The integrated memory controller of the i7 cpu's do a good job of feeding the cpu with data from ram. As a result, real application performance or FPS (vs. synthetic benchmarks) is not much affected by ram speeds or timings. Think 2-3%. Do not spend much extra on faster ram or better timings. DDR1600 is about as good as you need to get.
Ok thanks! What is a good 1600 memory to get? I will be doing a lot of gaming also.
For any ram you are considering, do your own homework.
Go to the ram vendor's web site, and access their configurator.
Corsair, Kingston, Patriot, OCZ and others have them.
Their compatibility list is more current than the motherboard vendor's QVL lists which rarely get updated.
Enter your mobo or PC, and get a list of compatible ram sticks.