Basically what everyone is saying.
i5 is more cost efficient compared to the i7. Not many games will play noticeably faster on an i7 compared to the i5.
16gb isn't needed for gaming either. 8gb is really all you need and you'll still have room to multitask.
The graphics card is a quite a bit weak for a system at this budget. You could get a r9 290 which is significantly stronger and able to play most games on highest settings. The gtx 750 is a card meant for low power budget gaming.
As for the case, if you still want the case you have up there, you could sacrifice on the r9 290 and get a gtx 770 which would still play games at a higher setting compared to the gtx 750.
At a 1200$ budget, you could throw in a SSD for the build, it'll help make boot up a lot faster.
PSU wise, seasonic is a more well-known brand and make very reliable psus.
The money you save there you could throw into other parts which would make it a better rounded system.
If you're not overclocking, you could go with a Xeon e3 1230v3, which is almost an i7 but at the price of a i5. If you go this route, you could pick a cheaper z97 board if you plan on running SLI/Crossfire in the future, or you could get a H97 motherboard and get rid of the CPU cooler. The money could be moved elsewhere if you want.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor ($219.99 @ Newegg)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.99 @ Amazon)
Motherboard: ASRock Z97 EXTREME4 ATX LGA1150 Motherboard ($130.99 @ Newegg)
Memory: Mushkin Redline 8GB (2 x 4GB) DDR3-2400 Memory ($84.99 @ Newegg)
Storage: Sandisk Solid State Drive 128GB 2.5" Solid State Drive ($54.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($54.99 @ NCIX US)
Video Card: Gigabyte Radeon R9 290 4GB WINDFORCE Video Card ($379.99 @ Newegg)
Case: Rosewill CHALLENGER ATX Mid Tower Case ($39.99 @ Amazon)
Power Supply: SeaSonic S12II 620W 80+ Bronze Certified ATX Power Supply ($71.30 @ Newegg)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($13.99 @ Newegg)
Operating System: Microsoft Windows 8.1 - 64-bit (OEM) (64-bit) ($95.98 @ OutletPC)
Total: $1177.19