So I guess my initial questions are:
1) If I'm NOT planning to overclock - is 1600 the way to go? Or will faster RAM work out of the box?
2) With stock cooler - is overclocking stable or risky? Then how does this affect my choice of RAM?
3) Will getting 2x4GB give better performance than 1x8GB (because of the whole dual channel thing?) - I was planning on buying 8 now then upgrading to 16 in the future. So also, will 4x4GB give better/worse performance than 2x8GB?
Basically - I didn't plan on overclocking, but since I've wound up with a K cpu and Z87 - it almost seems a shame not to. Don't really know where to start though.
I don't want to gimp myself on memory, but don't want to waste money on getting something I can't use to its full capacity!
1) Personally I would go with 1600 RAM modules. You can buy faster RAM but you won't really notice a difference.
2) Overclocking is NEVER recommended with the stock cooler that came with your CPU. The stock cooler is designed to keep your CPU within its thermal window under stock frequency.
3) You will gain a slight performance increase if you run your memory in dual channel mode, but once again you may not be able to notice the difference.