Love your build, but with an extra $100 to spend, you have two great options.
Option 1. Add a ssd.
PCPartPicker part list:
http://pcpartpicker.com/p/3LMZI
Price breakdown by merchant: http://pcpartpicker.com/p/3LMZI/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3LMZI/benchmarks/
CPU: Intel Xeon E3-1230 V3 3.3GHz Quad-Core Processor ($249.98 @ SuperBiiz)
Motherboard: ASRock B85 Pro4 ATX LGA1150 Motherboard ($69.99 @ Amazon)
Memory: A-Data XPG V1.0 8GB (2 x 4GB) DDR3-1600 Memory ($63.99 @ Newegg)
Storage: Crucial M500 120GB 2.5" Solid State Disk ($72.00 @ Amazon)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($54.43 @ OutletPC)
Video Card: MSI GeForce GTX 770 2GB TWIN FROZR Video Card ($299.24 @ Amazon)
Case: Fractal Design Define R4 w/Window (Black Pearl) ATX Mid Tower Case ($108.98 @ Best Buy)
Power Supply: Antec High Current Gamer 620W 80+ Bronze Certified Semi-Modular ATX Power Supply ($64.99 @ NCIX US)
Total: $983.60
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-05-17 14:36 EDT-0400)
Option 2. Upgrade to R9 290
PCPartPicker part list:
http://pcpartpicker.com/p/3LN37
Price breakdown by merchant: http://pcpartpicker.com/p/3LN37/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3LN37/benchmarks/
CPU: Intel Xeon E3-1230 V3 3.3GHz Quad-Core Processor ($249.98 @ SuperBiiz)
Motherboard: ASRock B85 Pro4 ATX LGA1150 Motherboard ($69.99 @ Amazon)
Memory: A-Data XPG V1.0 8GB (2 x 4GB) DDR3-1600 Memory ($63.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($54.43 @ OutletPC)
Video Card: Gigabyte Radeon R9 290 4GB WINDFORCE Video Card ($379.99 @ Amazon)
Case: Fractal Design Define R4 w/Window (Black Pearl) ATX Mid Tower Case ($108.98 @ Best Buy)
Power Supply: Antec High Current Gamer 620W 80+ Bronze Certified Semi-Modular ATX Power Supply ($64.99 @ NCIX US)
Total: $992.35
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-05-17 14:38 EDT-0400)