Here is my new build, i went for the larger PSU for potential future proof and SLI, I am looking for purchase in the next day. Any critiques, want to keep it in the £1400 range. Any comments would be appreciated.
I don't know about the MSI or the Asus but I did purchase 2 Gigabyte Windforce cards. Card for Card 1vs1 they are performing as good as my friends GTX 680 in BF3 with maxed ultra settings at 190x1080p. I can vouche for the performance, that its amazing and can overclock extremely well. I sit at 1.25Ghz overclocked without breaking 60c temps full load.
Also if you do not plan on overclocking your CPU, you don't need the cooler as wr6133 stated and you do not need a Z77 Motherboard. You could drop down price on both of those pieces. As well if this is mainly for gaming you do not need 16gb ram, 8 is overkill for the forseeable future. Since you are getting a 120Hz monitor use the money you will save on the parts suggested and put it into a 680 to make sure you take full advantage of that 120Hz and possible SLI that card in the future to make sure of it!!! ^_^ but in a more realistic sense, go with the 670 and SLI it, it'll give that monitor a run, one wont push it quite yet but 2 will.