Some reasons to consider keeping the SSD:
It'll significantly increase boot and loading times, and I really won't make a good budgeted build without a SSD today.
770 would not be an upgrade, its at par with 280X, besides being a gen older now, as the 900 series has arrived. If you want something better than 280X, consider 970. 770 is no doubt good but 2GB VRAM is a deal breaker IMO considering more and more games are putting heavier textures on GPU thus requiring more VRAM.
Also,
The MoBo is good for the price, but you consider the excellent GA-970A-UD3P there, 8+2 is excellent for FX 8, better than the one currently in build.