I would get the i5 3570K instead of the i7 if only gaming. Save $100 and add it to your GPU funds.
Also change to power supply to something made by Seasonic http://us.ncix.com/products/?sku=59616&promoid=1101
650W is more than enough for your build. Corsair CX psus are built cheaply.
As for the GPU with your $200 budget right now, go with the R9 270. If you can stretch for $250, GTX 760 is the clear choice. For $350, GTX 770.