I'd replace the CPU/mobo with i5 4670k and a Z87. Slightly better performance and lower power consumption for around the same price.
Also, two 670s for that price...not a great deal. Agree that two 4GB 770s would most likely last longer into the future, and are not that much more. I would not go with Crossfire until they get the stuttering issues worked out, if you'd rather get 2 Radeon cards.
I already had the one Gtx 670 ftw and the I 5 from last year so I couldn't really get the 770 or the 4560k --- I5 3570k 4.2 Ghz | 2 Gtx 670 ftw 's sli| 1 TB HDD | 16 GB RAM | corsair TX 750 | Samsung 840 pro 256GB | Asus P8 Z77V - LK | Cooler master HAF Tower
I already had the one Gtx 670 ftw and the I 5 from last year so I couldn't really get the 770 or the 4560k
If one 670 isn't performing to your liking you could get another, but if it's working well enough for the games you play I would wait til newer cards come out and get one of those. --- Pearl Code: 0731 1228 8254 White Code: 0862 2790 1982 SSBB: 0989-1461-9542