This system is all about maximum lifespan and stability. The MB/CPU/RAM/SSD are only a fraction of the overall cost. Because of this I went with the higher end. It was going to be a Intel i9, then i7 7700k was tested, then i5 6600k. The i5 performace perfect and the is priced lower than the 7700k.
There is absolutely zero difference between i5-6600k and g4560 in terms of "maximum lifespan and stability". If anything, g4560 will run a little bit cooler, consuming tiny bit less power. 6600k is a waste of money on a mining rig. And i9 is just lol. The only reason I commented on this is because you said that "low end standard CPU's, ie G4400 will not work beyond 8 GPU's, 9 MAX on windows". So I was curious about why they will not work. G4560 works.