The 990XA has 8+2 phase power, which is good for CPU overclocking.
However, it will not do crossfire or SLI well. The PCIe slots will do x16 / x8 and x4.
A 990FXA board will support 2 GPUs at x16 / x16. If you plan to crossfire or SLI, you need a 990FXA board.
If you aren't going to crossfire or SLI, you will get the same quality power circuit and PCIe performance from something like a Gigabyte GA-970A-UD3P. You might be able to save a little money and get the same quality with the 970 board.