An appropriate gpu would budget 2x the cost of the cpu. That would be something like a GTX960.
A side monitor adds nothing to the load on the graphics card while gaming.
If your monitors are 1080P, you will gain little past a GTX970.
MY thoughts on the rest of the build:
1. FX-6350 is ok for what it is. But the cores are weak.
Few games can make use of more than 2-3 cores, so the extras are not much help.
If your games are sims, strategy or mmo types, buy a cpu with stronger individual core speeds.
Passmark shows fx-6300 single thread rating of 1484.
By comparison, the equally priced i3-4170 is 2140.
Changing to a 8350 gives you 8 cores, but they are individually still slow, at 1506.
And... the i3-4170 will run just fine on the stock cooler.
You really might consider doing a Skylake build for the long term.
The cheapest i5-6400 at $ 210 has a single thread rating on all 4 cores of 1927.
Again, no extra cooler is needed.
Motherboard and ram costs will be comparable.
2. A GTX970 card will only need 500w.
I would buy a better quality psu for less.
The evga is a tier 3 unit:
https://community.newegg.com/eggxpert/computer_hardware/f/135081/t/45344.aspx?Redirected=true
I would look at Seasonic for top quality.
I might buy this Seasonic s12II 620w unit for less. It will run even a GTX980ti.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151096