first off that is a very fine build.
but you really don't need an i7 for what games you are looking to an i5 3570K will be just fine. the p8z77-v pro is a great motherboard, i have one, but if you want to trim a few dollars off the p8z77-v lk will work fine. it may not have as many phases for cpu but unless you're looking to benchmark and get high stable overclocks, it won't matter. and also a 750 watt PSU is much more than you need unless you are sure you are getting another 7970 later. a seasonic G series or rosewell capstone 550 watt are great choices also.
not to completely tear apart your build but what i am looking for is to get a GTX 780 instead of the 7790 (though its a great card itself and will serve you well) but if you...