Water cooler is good for overclocking.
RAM is good. 1866, 2133 and 2400 are all OK. But 1866 is best because you can get cas 9 and 1.5V. Cas 9 1866 is the same speed as cas 10 2133 or cas11 2400.
I think an SSD is a great idea. I use 120gb for my OS and not much else. With 250GB you can put your most useful software eg games, office etc for fast load times.