I see no problems with this build except for psu.
Because 750w is too much and you would need so much only if you add second videocard later. What you need is reliable brand psu from antec/corsair/xfx/silverstone. 550w should be enough. at least 80+ bronze quality
so, another psu will come cheaper and i'm strongly recommending to put more money into videocard (my guess is you're building gaming pc?) Radeon 7850 will be a noticeable improvemnt over 7770 for not so much money. If you still come up short, you can get cheaper motherboard of 970 chipset, because frankly, 140$ for mobo is too much. I see no benefit for usual user in getting mobo that costs more that ~ 120$