First time building a pc

[Pwnz4us]

I'm planning to do my first pc build this month and I'm wondering
1# if the parts I've chosen are good.(Is their enough clearance for the ram and cpu cooler ; should I get a better cpu cooler? Should I pick other parts instead )
2# if the psu is overkill (I will probably add a second gpu and overclock my cpu somewhere down the road)
3# Can someone recommend a good ups(uninterruptable power supply) for my build.
4#If the case I've chosen is good for the build and future upgrades.

Specs
Processor: I7-6700k
Graphics Card: Zotac GTX 1070 AMP! 8GB
Motherboard: Asus z170-A
RAM: GSkill Ripjaws V 16GB Dual DDR4 3200
SSD: Samsung 850 Evo 250GB
HDD: 2x Western Digital Caviar Blue 1TB
PSU: Corsair RM850i 80+ Gold Full Modular Power Supply
Case: Fractal Design DEFINE XL R2 (Black Pearl)
Edit:Cpu cooler is nh-u12s(or can someone recommend an air cooler so I can do some overclocking because I don't trust water coolers since they might leak)

Note: English is not my native language so bear with any spelling or grammatical errors you find. If you have any questions about my build feel free to ask me on why I did that or picked that.

Edit:
Note#2: I actually don't know how to pick an optical drive to use to install Windows on. Will a LiteOn IHAS524, Asus 24X DVDwriter SATA DRW-24D5MT, HP 1265i 24X Multiformat DVD Writer, or a LiteOn IHAS124 24x Multi Format DVDWriter suffice. Those are the only 4 I can find at the store where I'm buying all the parts.

 

[xFeaRDom]

1: The components are a great set up, except I would probably choose a Samsung 850 Evo, and 1 2TB HDD instead of 2x1TB.

2:The PSU Is definitely overkill, but if you plan to add a second GPU, then it should be fine, I'm guessing you will have SLI 1070s (I believe) and it's recommended to have something around that to run both cards and the rest, including the overclocking of the GPUs (I'm guessing you will do that) and the CPU, then it should be a great PSU to use, it may be a little overkill for now, but it will be worth it when you get the second 1070/GPU.

3: Can't really answer that, do not know about good UPS'

4: The case looks good, and should have enough room for all of the components you're on about purchasing, you did not list the CPU Cooler so I cannot judge, but it has clearance for up to 170mm - If you're thinking of a major overclock on the CPU, a watercooling system would be best, as an air cooler will only allow you to do a slight overclock, and that's somethings like the Noctua or 212 Evo.

 

[Pwnz4us]

Although most of my questions have been answered some of the few questions I would like answered have been edited in but thanks anyway for everything guys

 

[King Dranzer]

Please can you also provide budget.

 

[Isokolon]

as for the Optical Drive it depends on what you're using it for.
if you got a lot of DVDs that you plan on playing with it, creating and or high quality ripping Audio CDs then get a good drive (35€+)
if you need it to install Windows + your chipset & LAN driver, you can go with the cheapest you can find.
Generally I'm not that much a fan of LiteOn drives as the cheaper ones are louder than they have to but if you (like me) barely use it, then it's fine.
I'm using a 19€ Samsug drive for years now and never had an issue with it