If he can afford to drop $50 extra, here's what I would recommend :
PCPartPicker part list:
http://pcpartpicker.com/p/3qtBC
Price breakdown by merchant: http://pcpartpicker.com/p/3qtBC/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3qtBC/benchmarks/
CPU: Intel Core i5-2500K 3.3GHz Quad-Core Processor (Purchased For $120.00)
Motherboard: ASRock P67 Extreme4 Gen3 ATX LGA1155 Motherboard (Purchased For $0.00)
Memory: Corsair XMS3 8GB (2 x 4GB) DDR3-1333 Memory ($62.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($54.98 @ OutletPC)
Video Card: MSI GeForce GTX 770 2GB Video Card ($319.99 @ Newegg)
Case: Cougar Solution (Black) ATX Mid Tower Case ($36.99 @ Mwave)
Power Supply: Corsair Builder 600W 80+ Bronze Certified ATX Power Supply ($39.99 @ Newegg)
Optical Drive: Asus DRW-24F1ST DVD/CD Writer ($14.99 @ Newegg)
Total: $649.93
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-04-12 12:42 EDT-0400)
Otherwise, just drop down to a GTX 760.