Jack I've also been rereading your thread again and many of your dump files have been Bugcheck 124 with a machine check eception. Now as well as RAM one of the main causes for this crash can be a weak power supply.
I've been trying to find an Orion 475W PSU so I can check on the specifications. One has to also consider how many amps a PSU gives out too as this is critical to the machine running stable.
Now your GTX 960 requires 20A to run properly:
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The Orion/Hec PSU I could find (Orion and Hec seem one and the same) is this one at newegg:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817339019
Some more info:
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I would consider replacing the power supply in any case asap.