Thoughts on gaming build

Solution
To be more future proof a GTX 970 would be a better option, other than that, you build will be perfect and will easily handle gaming for now until you need to crossfire.
This is more of a personal choice, but I'd stay away from XFX and stick to either ASUS, Gigabyte, or MSI if I were you. Specifically, I'd choose the MSI R9 290X Lightning for my GPU. A good colour match for your MoBo. Other than that, looks solid! Cheers!