YBS1, if I were you, I would have already bought that ram. No way could I have come as far as you have on your system and refuse the temptation from a perfect matching set of ram sticks like that. That's just me though.
Regarding power shutdown, wow, that actually happened? Crazy. I DO like that the system told you about a power issue. That's actually pretty great that its smart enough to know it had a power problem.
Regarding cards not OCing enough, try to keep in mind that most 980ti's all clock pretty much the same or at least pretty similar, at least based on what I've seen and read. Bottom line really is that your cards should be able to get stable around 1440-1500 boost, possibly a little more with no added voltage. If you add some voltage you can push a little past 1500. I settled on 1440 for a standard OC for mine, with no voltage added, and they are stable as can be and mine are reference cards.
You cards come factory OC'd it seems. I'd pay more attention to the total boost value rather than be concerned with only being able to add about 150 to the boost without voltage.
Looking good though. THAT RIG IS A BEAST and I do like seeing those 980ti's holding their own while surrounded by titans on that score board.