Upgrade or New build?

[xl Steins lx]

Im deciding between two options:
Upgrade: 
-Gigabyte GeForce GTX 970 G1 Gaming 4GB
-NZXT S340 Mid Tower Case Black
-Samsung 840 EVO Series 120GB SSD

Build: 
-Gigabyte GA-B85M-D3H Motherboard
-Samsung 840 EVO Series 120GB SSD
-G.Skill Sniper F3-12800CL9D-8GBSR 8GB (2x4GB) DDR3
-NZXT S340 Mid Tower Case Black
-Intel Core i5 4590
-Gigabyte GeForce GTX 970 G1 Gaming 4GB
-Salvaged GX 750W PSU from my old PC.
-Salvaged 2x2Tb HDD from my old PC.

Current PC:
-i7 970
-16Gb 1366 Ram.
-AMD HIS 6970

Will the i7 960 bottleneck my new GPU if i choose to only upgrade? I'm looking to play Witcher 3(Medium-High? Doubt any single card can run this on max), GTA V (Max), Far Cry 4(Max) at 1080p, possibly 2x1080p screens latter on. Which option is best?

Also if anyone could pick out a different build for me that will run those titles at those settings for Strictly $1500 AUD and under (from PC Case Gear only?) that'd be great!

PS: This particular build from PCCG looks pretty decent, should I just save the hassle of getting a friend to build my PC and buy a pre-built that comes with ease of mind? (I can't build things, anything.)

CPU: Intel® Core™ i5 4590 Processor
Motherboard: ASRock H97M-Pro4 Motherboard
Graphics: EVGA GeForce GTX 970 Superclocked ACX 2.0 4GB
Memory: Kingston Hyper X Fury HX318C10FK2/8 8GB (2x4GB) Blue
Solid State Drive: Kingston HyperX Fury 120GB SSD
Hard Drive: Seagate Barracuda 2TB ST2000DM001
Power Supply: Be Quiet! Straight Power 10 600W CM Power Supply
Case: Silverstone Raven RV05B-W Case with Window
Additional Lighting: PCCG LED Strip White 30cm
Operating System: Microsoft Windows 7 Home Premium 64bit OEM License
Warranty: 1 year return-to-base warranty on assembly, see individual product pages for warranty duration on each component

 

PSSSS: I don't OC. The games im playing right now are Guild Wars 2, League of legends, CS:GO, GRid 2, NFS and intending to play Witcher 3, GTA V and Far Cry 4.

[Prikk]

Your cpu is fine. Just upgrade.

[NoctHorn]

Your CPU is still good.  In fact, it still outperforms the haswell i5 in a synthetic benchmark.  Go with the upgrade.

[spartaman64]

upgrade

[Lotus]

It depends on what kind of games you play, and how far of an OC you can get on your i7-960. If you play mostly games that can make use of 6+ threads, you're fine. If you play games that need strong single-core performance, it's time for an upgrade. I have my i7-920 @ 3.9 GHz and an i5-4460 DOES beat me in single-threaded performance, albiet not in multithreaded.