670 SLI sounds overkill for 1080p / 1200p. If it's triple monitor, then I'd be thinking of 4GB cards.
The Dominator platinum sound overkill when you can have 16GB for the same budget.
And I don't like high ram heatsinks, but that's OK if you are planning on using water cooling.
Besides looking at your sig, why the CPU / RAM upgrade? Clock the 2500K to 4.4-4.6GHz and you should be golden. RAM won't matter for gaming.