If you buy a PSU, don't get a cheap one. Look for a Seasonic, Corsair (not the c series) XFX or Antec. They are pricey but well worth it. The cheaper ones many times don't put out the Power they claim, Have little to no safety features built in, and can take out your whole computer if they go out. We see it fairly often here. It's worth the investment. I wouldn't put a cheap PSU in any of my computers. The graphics card does not have to be similar to yours, any card will work. If you can borrow one, I'll tell you how to install it the right way. If your graphics card or PSU is bad, that could be the cause of your BSODs. It doesn't matter what card it is as long as your PSU can put out the necessary power for it. Any card will work as long as you know it's good. Remember, almost everything has passed except those things. Put one in at a time so if it fails still we will know it isn't that. I didn't test the Graphics card because I didn't think the card you had would take a stress test. We can try if you want to. The GPU and PSU are the only things that could be wrong in the hardware dept. If you can get another PSU and GPU to test and still have BSOD's we will know it is the Motherboard or CPU for sure. If it is the GPU or CPU, and you get that bundle you mentioned, you will have the same problems with it. So, it is important to check those last 2 things. Again, it does not have to be the same graphics card,
anything will do. The PSU is the heart of your system and a cheap one can take out the whole computer. Fact! BTW, EVGA is a good CPU I have read and they are fairly cheap, just get their better brands. I have also heard that Be Quiet is good. They are big in the EU but have just recently entered the US market, so I'm not familiar with them. But, I have a good friend in the UK and he says they are highly regarded there. I am not convinced the CPU is bad. It could be but I'm not so sure. But if we can eliminate the last 2 pieces of hardware, we will be reasonably assured that it is the motherboard or CPU. Everything else has passed with flying colors. Arc, is the best analysist we have. He is right on. I'm more of a hardware guy who knows a little about reading BSODs. That is why I was called in to your case, because I'm pretty good with hardware. This has baffled me, as nothing is happening the way it should. Also, I should have asked a long time ago, are you on a UPS? If so please let me know, and by pass the UPS and try running straight from the wall for a while. When a UPS starts going bad it will sporadically drop the power and cause the computer to BSOD. There is very little left to check. If you spend 1000 GBP or Euros on a new system and it does the same thing, you will not be very happy. That is exactly what I would do if it were my computer. I do not spend money until I know what the cause is. You can go broke replacing parts at random. I know, I've done it before.
My friend in the UK has the same rig as yours except he has the Ivy Bridge version. Those are a beast. We compete with each other all the time. I can overclock my rig to over 5 GHz and still can't beat him with his at stock. So, you have an excellent rig. I want you to be trouble free if you buy that bundle. I hope to go that route of a Haswell E as soon as we see some results so I know which Board to get. Read the user reviews on whatever board you get. I don't count on professional reviews. They get paid to give the boards a good review. It has to be very bad for them to give a bad review. The users will give you practical reviews and you will know which board is the most reliable, which is what you want. In the US this is probably the best site for user reviews. They sell so much stuff, you usually get more reviews. Just discount the ones who don't know what they are doing. You know plenty enough to pick them out.
Newegg.com - Computer Hardware, Motherboards, Intel Motherboards, LGA 2011-v3 you can sort it by most reviews, best rating or most anything else. Haswell is so new, there aren't a lot of reviews out now. I would stick with Asus. They have crappy technical support, but so does everyone else. But, in my opinion they build the best boards. There are a few brands I wouldn't use if they gave them to me free. Just trying to give you some honest advice and what I would do, in your case. You are very close to being able to increase the size of your testing farm, if you want to, or selling the parts and getting a pretty cheap upgrade. Just my 2 cents worth.