Gratz on purchases
As far as gaming goes a 4670K isn't that much faster than an i7 2600K when you factor in overclocks. Sandy is a hell of a lot more OC-friendly than Haswell, I would say getting a 4670K to 4.5ghz (as shown below) is about as uncommon as getting a 2600K to 4.9-5ghz.
As for my own rig, I'm finding myself contemplating just saying "fuck it" and going with a Corsair 550D + Noctua D14 for a maximum silence build...the ol' Sniper still looks lovely but it's starting to vibrate/rattle more and more as it ages.
A 550D would also technically let the GPU run cooler with a side intake which my current case doesn't allow.