You should get the 4690k over the 4670k. Although to be realistic, you don't need a $750 to build an mmorpg build. Take a look at this build:
PCPartPicker part list / Price breakdown by merchant
| Type | Item | Price |
|---|---|---|
| CPU | Intel Core i5-4460 3.2GHz Quad-Core Processor | $178.99 @ SuperBiiz |
| Motherboard | MSI H97M-E35 Micro ATX LGA1150 Motherboard | $79.99 @ Mac Mall |
| Memory | Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory | $59.99 @ Amazon |
| Storage | Crucial MX100 256GB 2.5" Solid State Drive | $99.99 @ Amazon |
| Storage | Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive | $52.75 @ OutletPC |
| Video Card | MSI Radeon R9 280 3GB TWIN FROZR Video Card | $189.99 @ Newegg |
| Power Supply | EVGA 500W 80+ Bronze Certified ATX Power Supply | $42.99 @ SuperBiiz |
| Optical Drive | Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer | $19.75 @ OutletPC |
| Prices include shipping, taxes, rebates, and discounts | ||
| Total | $724.44 | |
| Generated by PCPartPicker 2015-03-30 03:09 EDT-0400 |
Basically, a cheaper CPU/mobo combo that will still be great, a video card with 3GB of RAM (if you want), a cheaper but still good PSU, and an SSD to improve loading times. The SSD will give you a much more noticeable performance increase than the CPU will.