I would personally go with the 770 you have given as the MSI cooler cards are amazing and will outperform that 7970 on I think everything. But if your not in a rush and can deal with your current specs, whatever they are, then maybe wait for some deals, new cards etc.
*edit what ajl2011shooter said above is also very true and will save you money, unless you have 2-3 monitors or are at 2560x1600 or something then 2gb is more than enough
I am currently running a single Sapphire 7870GHz.
I was looking at more VRAM since I play modded Skyrim and hopefully the next TES. would the 3GB 7970GHz be good for that with the 384bit memory bus @ 5.7Ghz memory? or do you think the GTX 760 4GB with 256 bit bus @ 6GHz would be a better decision if the 770 never comes to a price I feel like paying.
I was looking at the MSI Gaming cards since they hookup and OC higher with the my MOBO since its MSI Gaming as well.
the 4gb gtx 760 is a gimmick, the graphics card can't use all that VRAM, so it's a waste of money, 2gb is more than enough, but if you do want lots of vram, get the 7950, comes with 384bit and 3gb VRAM, which it can actually use.