if your mobo already has DDR3-1600 then it shouldn't have any compat issues
7950 has a great overclocking potential but even at that the GTX670 is pretty much a clear winner.
BTW there's a MSI one that's $50 cheaper than your galaxy one...smaller factory OC but great deal.
MSI N670GTX OC GeForce GTX 670 2GB PCI-E w/ Dual DVI, HDMI, DisplayPort at Memory Express