Here's a better build for your purposes:
PCPartPicker part list / Price breakdown by merchant
| Type | Item | Price |
|---|---|---|
| CPU | Intel Core i5-6500 3.2GHz Quad-Core Processor | $194.99 @ SuperBiiz |
| Motherboard | Gigabyte GA-H170M-D3H Micro ATX LGA1151 Motherboard | $91.99 @ Micro Center |
| Memory | Crucial Ballistix Tactical 8GB (2 x 4GB) DDR4-2666 Memory | $44.99 @ Adorama |
| Storage | Crucial BX100 120GB 2.5" Solid State Drive | $56.99 @ Amazon |
| Storage | Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive | $47.99 @ Micro Center |
| Video Card | Gigabyte Radeon R9 390 8GB Video Card | $299.99 @ SuperBiiz |
| Case | BitFenix Prodigy M Midnight Black MicroATX Mini Tower Case | $85.05 @ Amazon |
| Power Supply | SeaSonic 520W 80+ Bronze Certified Fully-Modular ATX Power Supply | $62.99 @ SuperBiiz |
| Prices include shipping, taxes, rebates, and discounts | ||
| Total | $884.98 | |
| Generated by PCPartPicker 2016-04-24 11:28 EDT-0400 |
Actually good PSU, better graphics card for less money, 100% less orange case, you're not overclocking so you don't need an aftermarket CPU cooler.
I can't choose your mouse for you but I wouldn't get the G502 personally, it's way too heavy for precision aiming in shooters unless you have monstrous hands. I'd recommend something along the lines of a Zowie EC2-A. The monitor in your build looks fine. Again, personally, I wouldn't spend $50 on a non-mechanical keyboard - just grab a Logitech K120 for $15 and you'll save a good amount while getting a keyboard of basically the same quality.