Agreed that you should definitely go with the latest, well-priced 900 series. All else being equal, you should grab a single fast GPU over 2-cheaper SLI'd cards. More heat, noise, and driver issues, and not all games support SLI perfectly. That and buying one card now, gives you the option to add a 2nd in the future.
Next, in this price range, you can consider a 1440p monitor, or a 144HZ monitor, depending on your own preference. There are monitors just now coming to market that are both, but they come at a price premium.
CLC (closed loop water coolers) are a mixed bag. You get slightly cooler temps on the CPU itself, but some of the other components on the mobo don't get cooled as well, and you end up with a loud radiator on your case. I prefer the quiet (though bulky) Noctua D14 in this price range.
Here's my recommendation, just add a monitor. You can add another 980 down the road (although might want to bump up the PSU to 850W). The Case is kind of subjective. The Corsair Carbide, NXZT Phantom, and Fractal R4 series are all solid choices for a case.
If you have wiggle room, bump up to a larger SSD, or to a slightly faster Samsung 850 Pro. Also, if you have free money, look into a mechanical keyboard. It can make a huge difference in your every-day use, and gaming.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($279.99 @ Micro Center)
CPU Cooler: Noctua NH-D14 65.0 CFM CPU Cooler ($64.99 @ NCIX US)
Motherboard: Gigabyte GA-Z97X-UD3H ATX LGA1150 Motherboard ($135.98 @ OutletPC)
Memory: Crucial Ballistix 8GB (2 x 4GB) DDR3-1866 Memory ($94.99 @ Adorama)
Storage: Samsung 840 EVO 250GB 2.5" Solid State Drive ($129.99 @ Amazon)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($53.98 @ OutletPC)
Video Card: EVGA GeForce GTX 980 4GB Superclocked ACX 2.0 Video Card ($569.99 @ Amazon)
Case: Fractal Design Define R4 w/Window (Black Pearl) ATX Mid Tower Case ($89.25 @ Newegg)
Power Supply: XFX ProSeries 750W 80+ Gold Certified Fully-Modular ATX Power Supply ($89.99 @ NCIX US)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($13.99 @ Newegg)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($89.98 @ OutletPC)
Total: $1613.12
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-10-06 17:42 EDT-0400