how is this build for gaming? (need opinions!)

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4460 3.2GHz Quad-Core Processor ($166.95 @ SuperBiiz)
Motherboard: ASRock H97M Anniversary Micro ATX LGA1150 Motherboard ($67.89 @ OutletPC)
Memory: Crucial Ballistix Sport 8GB (2 x 4GB) DDR3-1600 Memory ($44.49 @ Newegg)
Storage: Crucial BX100 250GB 2.5" Solid State Drive ($83.99 @ Amazon)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($51.89 @ OutletPC)
Video Card: XFX Radeon R9 290X 4GB Double Dissipation Video Card ($259.99 @ Newegg)
Case: NZXT S340 (Black) ATX Mid Tower Case ($54.99 @ Micro Center)
Power Supply: SeaSonic 600W 80+ Bronze Certified ATX Power Supply ($56.98 @ Newegg)
Wireless Network Adapter: TP-Link TL-WDN4800 802.11a/b/g/n PCI-Express x1 Wi-Fi Adapter ($37.24 @ Amazon)
Total: $810.41
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-08-04 22:32 EDT-0400

Slight tweaks.

Hdd, get the WD instead. The SeaGate has a much higher failure rate, it's worth the 3 dollars. The 290x is actually better than the 390, and saves you money.

:edit: Nvm, I thought the 290x was better, it's slightly slower. If it's in your budget, get the 390.