Ditch the Cooler master PSU its junk. Get one from Antec, XFX, Corsair, Seasonic.
I personally would get an i3 and a $60ish b75 motherboard and use the saved money to get a gtx650ti. It will be better than the hd7770.
true cooler masters are not good, but i think you would be fine. Recommend switching to a corsair cx series though. Probably same price, but higher quality. It really depends on what series though, some cooler master psu's are decent. But i suspect your's is the extreme series which is bad.
If you dont plan on upgrading your cpu, stick with the current build. HOwever as tiny voice suggested, getting an i3 will allow you to upgrade if you are unsatisfied later on