Computer vs 4k

I'd go with this:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($319.99 @ NCIX US)
CPU Cooler: Noctua NH-D15 82.5 CFM CPU Cooler ($74.99 @ NCIX US)
Motherboard: Gigabyte GA-Z97X-Gaming GT ATX LGA1150 Motherboard ($188.98 @ SuperBiiz)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 Memory ($76.50 @ Newegg)
Storage: Samsung 840 EVO 500GB 2.5" Solid State Drive ($239.99 @ Amazon)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($83.49 @ OutletPC)
Video Card: Sapphire Radeon R9 290 4GB Tri-X Video Card (3-Way CrossFire) ($410.98 @ SuperBiiz)
Video Card: Sapphire Radeon R9 290 4GB Tri-X Video Card (3-Way CrossFire) ($410.98 @ SuperBiiz)
Video Card: Sapphire Radeon R9 290 4GB Tri-X Video Card (3-Way CrossFire) ($410.98 @ SuperBiiz)
Case: Enermax ECA3280A-BR ATX Mid Tower Case ($67.98 @ Newegg)
Power Supply: EVGA SuperNOVA 1300 G2 1300W 80+ Gold Certified Fully-Modular ATX Power Supply ($184.99 @ NCIX US)
Optical Drive: Asus BW-12B1ST/BLK/G/AS Blu-Ray/DVD/CD Writer ($47.99 @ Newegg)
Fan Controller: Aerocool F6XT Fan Controller ($19.99 @ Mwave)
Total: $2537.83
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-08-31 15:16 EDT-0400

Modern hardware is still not ready for 4k, so you probably won't be able to run everything on ultra.
 
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