Thanks again. I think I have undermined the importance of a computer's video card in the past. I will try to find something better than the 660. But I can't go as high as the 7970 due to its price (about $450!).
I went for a 2G version of a 7790 (which is quite a low-medium end card but with lots of graphic memory, and highly power efficient). It is no problem at all for Civ at 1900X1200 - you really don't need that high end of a card for Civ. Mine cost like $160. Rest of the system is:
4470 (not K, because the K lacks some instruction extensions which I suspect might become important in future). Only get the K if you plan to overclock
32G 1600 RAM
960G SSD
FT02 case (this thing ROCKS - I'm SO glad I spent big on the case - its utterly silent)
550W platinum efficiency PSU