Originally Posted by
tubnotub1
That's unfair, maybe the OP wants to future proof his rig and is just a bit more forward thinking than you are. A single titan isn't going to max out every game for the next three years, but it wouldn't surprise me if a pair of them will, they will certainly come closer than a single one.
As to SLI, I have been running SLI since the 8800 GTX (SLI and Tri-SLI) and I don't plan on ever going back. With today's drivers microstutter is kept to a minimum and the vast majority of games are supported upon release. I think you should pull the trigger OP once you find the cards in stock!
Edit: It can get noisy, maybe think about replacing the stock HSF if investing in a decent pair of headphones.