like I said. don't do it. Overclcoking in general is a sure way to shorten the life of your system.
With memory you're changing the voltage and timings just like a CPU.
You'll wind up burning it up and kicking yourself in the b*tt.
I am totally against overclocking. I destroyed a new CPU by doing it (and I "knew" what I was doing.) And if you plan to watercool, it better be cost effective, generally it's not.