since you have room inyour budget i would get a better mobo 990fx is the best amd chipset, also dont forget a psu.
I feel that in this budget 990 mobo will be excessive, 970 will do
asrock 970 extreme 3 Mobo is a solid board for a good price no need to go past that on a budget build. If your building a budget PC what's its main purpose? the 8 core cpu seems a little excessive if it will be purely for gaming on that budget. Also for pretty much the same price as your current gpu Newegg has the XFX 7850 2gb gpu for sale. Nice to have if you plan on running high resolutions.