Judge this budget build

[CaptEinstein]

Building this PC for my cousin. He plays at 1080p, he doesn't do any other serious things other than just gaming. So, it's a budget build. We already have the case and PSU so the other components needed are just GPU, CPU and Motherboard. These are the parts I think that'll help play next-gen triple A titles at 1080p at about high to ultra settings depending on the game. I'm still deciding on the components, so suggestions are appreciated and NEEDED.

NOTE: Since we have the case and PSU covered. We just need to spend around $300 - $400 for the parts below. So, don't go over the budget.

CPU: Either AMD FX-6300, Athlon X4 860K. I want a reliable and cheap budget gaming CPU that'll help run almost any game I throw at it. Not less that 4 cores and unlocked and easily overclockable. So the Pentium g3258 eventhough really easily OC'd, it's not an option for this build (It's dual-core). I'm open for suggestions though.

GPU: I'm thinking Radeon R9 280X 3GB, not sure about GTX 960 though. I've seen benchmarks and the 280X is the faster card plus having 1GB more on VRAM, though wrecking the power consumption. I'm up for suggestions and again. It's a budget build.

MOBO: MSI 970 GAMING AM3+ Motherboard OR Gigabyte AMD AM3+ GA-970A-DS3P Motherboard. I want GREAT OC ability to get most out of the CPU and I want consistency. I don't want it to blow up. So SUGGESTIONS PLEASE.

 

[ykki]

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4150 3.5GHz Dual-Core Processor ($99.99 @ SuperBiiz)
Motherboard: ASRock H97M PRO4 Micro ATX LGA1150 Motherboard ($74.93 @ SuperBiiz)
Video Card: Gigabyte Radeon R9 280X 3GB Video Card ($239.99 @ Newegg)
Total: $414.91
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-04 08:18 EST-0500

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PCPartPicker part list / Price breakdown by merchant

CPU: AMD Athlon X4 860K 3.7GHz Quad-Core Processor ($69.75 @ OutletPC)
Motherboard: ASRock FM2A88X Extreme4+ ATX FM2+ Motherboard ($76.99 @ Newegg)
Video Card: Gigabyte Radeon R9 280X 3GB Video Card ($239.99 @ Newegg)
Total: $386.73
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-04 08:20 EST-0500
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PCPartPicker part list / Price breakdown by merchant

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($89.99 @ SuperBiiz)
Motherboard: Gigabyte GA-970A-UD3P ATX AM3+ Motherboard ($79.99 @ SuperBiiz)
Video Card: Gigabyte Radeon R9 280X 3GB Video Card ($239.99 @ Newegg)
Total: $409.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-04 08:21 EST-0500

Here are your options.
I would gO for the 1st one because the upgradability it offers.
The second and third one are just as good but they don't feature a cpu cooler yet.
I would suggest the third one if you want overclock-ability. Just add a cooler later.

 

[SPgamer007]

If you can add 70$ more,this rig could be a better choice.

PCPartPicker part list: http://pcpartpicker.com/p/8QNHzy
Price breakdown by merchant: http://pcpartpicker.com/p/8QNHzy/by_merchant/

CPU: AMD FX-8320 3.5GHz 8-Core Processor ($133.99 @ SuperBiiz)
Motherboard: Asus M5A99FX PRO R2.0 ATX AM3+ Motherboard ($108.99 @ SuperBiiz)
Video Card: Asus Radeon R9 280X 3GB DirectCU II Video Card ($229.99 @ Newegg)
Total: $472.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-04 08:28 EST-0500

or else ..

PCPartPicker part list: http://pcpartpicker.com/p/Bhfj23
Price breakdown by merchant: http://pcpartpicker.com/p/Bhfj23/by_merchant/

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($89.99 @ SuperBiiz)
Motherboard: Asus M5A97 R2.0 ATX AM3+ Motherboard ($84.99 @ SuperBiiz)
Video Card: Asus Radeon R9 280X 3GB DirectCU II Video Card ($229.99 @ Newegg)
Total: $404.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-04 08:31 EST-0500

 

[CTurbo]

The i3 is simply the best option at this price range. AMD does not compete in gaming.

PCPartPicker part list: http://pcpartpicker.com/p/GpJ8CJ
Price breakdown by merchant: http://pcpartpicker.com/p/GpJ8CJ/by_merchant/

CPU: Intel Core i3-4150 3.5GHz Dual-Core Processor ($99.99 @ SuperBiiz)
Motherboard: ASRock H97 Anniversary ATX LGA1150 Motherboard ($66.99 @ SuperBiiz)
Video Card: Asus Radeon R9 280X 3GB DirectCU II Video Card ($229.99 @ Newegg)
Total: $396.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-04 08:36 EST-0500

 

[CaptEinstein]

The i3 is simply the best option at this price range. AMD does not compete in gaming.

PCPartPicker part list: http://pcpartpicker.com/p/GpJ8CJ
Price breakdown by merchant: http://pcpartpicker.com/p/GpJ8CJ/by_merchant/

CPU: Intel Core i3-4150 3.5GHz Dual-Core Processor ($99.99 @ SuperBiiz)
Motherboard: ASRock H97 Anniversary ATX LGA1150 Motherboard ($66.99 @ SuperBiiz)
Video Card: Asus Radeon R9 280X 3GB DirectCU II Video Card ($229.99 @ Newegg)
Total: $396.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-04 08:36 EST-0500

How will it benefit from dual core? Could you care to explain.

 

[CTurbo]

Because the AMDs have terribly weak single core performance, and Intel has very strong single core performance. That i3 is somewhere between 40-50% stronger per core and that more than makes up for having less cores. The i3 also has hyperthreading which allows it to handle 4 threads at a time. If you look at some benchmarks you'll see what I'm talking about. The i3 even beats the 8 core FX8350 in a lot of games.

 

[ykki]

Reasons to get the i3=
If you are upgrading frequently.
If you want the best up front performance without going into the hassle of overclocking.
Great single threaded performance(great for gaming)

Reasons for getting the 6300.
Cheap.
With the right cpu cooler (and mobo) it can be a beast of a budget cpu.
Does not give you the best up front performance but overclocking can alleviate that.
Good multitasking performance (but the i3 doesn't lack here either).

Overall I would get the i3 if you don't want to overclock.