Need help with PSU

Solution
That is an excellent psu, sufficient even for a GTX1080.

Some comments on your build:

1. Why not build with current gen?
I5-7600K and a Z270 motherboard should not cost much more.

2.Noctua NH-D14 is an excellent cooler, but HUGE.
Look at the equally effective NH-U12s, NH-U14s, NH-D15s. The s variants have been reengineered to clear ram and graphics cards in the first pcie slot.
I needed an insulating shim when I used a D14 to clear my graphics card back plate.

3. 120gb is too small for a C drive.
many things default to the "C" drive.
When a SSD nears full, it will lose performance and endurance.
240gb is the recommended minimum.

If you can go 240gb, or 500gb you may never need a hard drive.

You can defer on the hard drive...
A 550W PSU is indeed recommended, giving you a little room. The one you've picked is of very good quality. Personally, I (mostly) only recommend PSU's from EVGA and Seasonic as they use higher quality components, so the one you've linked is definitely a good pick!
 
That is an excellent psu, sufficient even for a GTX1080.

Some comments on your build:

1. Why not build with current gen?
I5-7600K and a Z270 motherboard should not cost much more.

2.Noctua NH-D14 is an excellent cooler, but HUGE.
Look at the equally effective NH-U12s, NH-U14s, NH-D15s. The s variants have been reengineered to clear ram and graphics cards in the first pcie slot.
I needed an insulating shim when I used a D14 to clear my graphics card back plate.

3. 120gb is too small for a C drive.
many things default to the "C" drive.
When a SSD nears full, it will lose performance and endurance.
240gb is the recommended minimum.

If you can go 240gb, or 500gb you may never need a hard drive.

You can defer on the hard drive unless you need to store large files such as video's.
It is easy to add a hard drive later.

Samsung 850 EVO is a good choice for performance and reliability.

4. Best to bite the bullet and buy windows 10.
 
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