If you're planning to get an I5 fairly certain you have to have ddr4 ram otherwise it just breaks your CPU within a year. At least that's what I was told with my i5-6600. I'm not sure whether your CPU is skylake however I know skylake does need ddr4 ram.
I know its a UK site, it migt work where ever. But if it doesnt it gives you a compatability filter so it will even tell you if stuff is too big for the case , what will work with what etc! https://uk.pcpartpicker.com
I would get a newer generation CPU and motherboard, along with the RAM necessary (DDR4, I5 6600K and a Z170 mobo)
Get the GTX 1060, it sports better performance and is cheaper (In Denmark atleast)
That PSU is waaaaaaaaaaay overkill. You will not need 850 watts for anything but SLI.
Also, getting the K overclockable version of the CPU means nothing when getting a motherboard that technically only allows overclocking of Intel Pentium processors. Buy a Z170 motherboard.
I'd buy an SSD to boot your PC from, as it improves OS start-up times A LOT
Here are some questions.
Why use an M-ATX motherboard when your case supports full-size ATX? (price, I guess)
What CPU cooler are you planning on getting?
Why the giant HDD?