Okay lets start with the Power Supply.. Think about it like this, the PSU is the Heart to the build, if it fails what is going to pumb the blood around the body? You want to buy the best possible Power supply for you're build, and seeing that you have the AMD FX 9590, The chip alone uses over 200W, you want to get a decent Power supply, I currently own the Seasonic M12II and it is quite expensive but was defiantly worth the investment.
I'd recommend either a Tier 1 or High quality Tier 2 PSU.
Here is some recommendations:
http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html
Now to the Graphics card:
R9 270 is a good GPU no doubt, But the peformance boost you will be expecting.. its a dream, i currently own the R9 390 and i love it, i have also owned the GTX 970 and the 3.5Gb memory issue buzzed me like crazy, I would recommend grabbing a R9 290/x as they go for a really good price at the moment, you can easily grab one for a bargain! but keep in mind that you will probably want to grab a minimum 700W Power supply or even 800W for running that FX chip.
In the end it depends what road you take,
970
-Low power consumption
-Great overclocking capabilities
-0.5GB memory issue
-Great Price per performance
R9 390/290
-High power consumption
-Great performance (290 has amazing performance for the money)
-390- 8GB Vram
I would recommend either grabbing a Corsair, Seasonic or silverstone PSU, I usually would say EVGA but they have had a few issues going by.
Good Luck-Ender