Will this computer work for streaming WoW and LoL on max settings and will there be any issues building it? Specs: MSI Z17

Your computer will be capable of running the games at high/max textures and quality with no problems.

However when you stream games it is heavily CPU intensive meaning that you could potentially notice some stuttering in game. I would recommend upgrading your CPU to one with hyper threading, such as the i7-6700k. Furthermore, you would most likely stream at 1080p, 30fps so an upgrade to 16GB of RAM would eliminate any problems with steaming and losing frames for the viewers

For streaming WoW and LoL you should be okay. They're both games that only use 1-2 CPU cores, and you have 2 extra for streaming.
But you may have to manually assign core affinities so the streaming software isn't using the same cores as WoW and LoL. https://bitsum.com/processlasso/

I assume the reason you're getting a z170 board but a non-k Skylake CPU is because you know you can overclock the locked skylakes with them. But if that's not why, then you don't need a z170 board, an h110 will run it the same.

You're getting kind of a weak CPU though, if you get a 6500 or 6600(k or no k) you'd be better off, as the price difference isn't that big the performance will be fairly significant.

You don't need an aftermarket cooler like the 212 evo unless you're going to overclock.

I think the PSU you listed is good, but it actually might not be, and i'm not sure if they make them anymore so i'm curious where you're getting yours.

drop to a gtx 960 or 760 and get an i7, you will want the hyper threading for streaming at a good resolution or you could get a Xeon CPU

Necessary, no.

What's your actual budget for the system, and what else do you need?

those games rely on CPU much more than GPU a gtx titan x with an fx 4130 would be outperformed by a i5 4460 running integrated on those games most likely

You can't afford an i7 and you don't need one, not for WoW and LoL. For fancier AAA games you'll need more CPU power to stream them, but you can run them just fine. You don't have a great deal of HDD space right away, but you can add a 1TB HDD for only $50-60 later on. The SSD will help you load WoW and LoL faster than most others, but the limited space will prevent you from really being able to record videos.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-6500 3.2GHz Quad-Core Processor ($204.99 @ Newegg)
Motherboard: *Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard ($55.38 @ Newegg)
Memory: *G.Skill NT Series 16GB (2 x 8GB) DDR4-2133 Memory ($59.49 @ Newegg)
Storage: *Sandisk Z400s 256GB 2.5" Solid State Drive ($71.99 @ NCIX US)
Video Card: EVGA GeForce GTX 960 2GB Superclocked Video Card ($184.99 @ SuperBiiz)
Case: *Xigmatek Spirit M MicroATX Mini Tower Case ($24.99 @ Newegg)
Power Supply: *EVGA 500W 80+ Bronze Certified ATX Power Supply ($43.57 @ Mac Mall)
Optical Drive: *Lite-On iHDS118-04 DVD/CD Drive ($12.89 @ OutletPC)
Operating System: *Microsoft Windows 8.1 OEM (64-bit) ($89.99 @ NCIX US)
Total: $738.28
Prices include shipping, taxes, and discounts when available
*Lowest price parts chosen from parametric criteria
Generated by PCPartPicker 2016-02-23 19:13 EST-0500

Building your own computer is easy. Building it takes 2-3 hours, and installing windows takes about 30mins to 45mins, and after that downloading and installing drivers takes another 30-45 mins. After all that, have it download windows updates at night, it may take a 2-4 passes to get them all.

Building a PC:
https://www.youtube.com/watch?v=VIF43-0mDk4
Installing Windows:
https://www.youtube.com/watch?v=4zAdwedmj1M

Protip for installing drivers safely, install them one at a time and restart the computer after each install to avoid breaking the OS, which can happen if you try to install them all at once.

Streaming
You can try OBS since it's free:
https://obsproject.com/
And here's how to set it up for local recordings, start at the recommended crf 15, and lower the number for higher quality and higher file size recordings, or raise it for slightly lower quality and smaller file sizes.
https://obsproject.com/forum/resources/how-to-make-high-quality-local-recordings.16/
And to set it up for twitch:
http://help.twitch.tv/customer/portal/articles/1262922-open-broadcaster-software


edit:

Saw the $850 budget, puts you in range of an i7, which will kinda help with streaming, but not with gameplay.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-6700 3.4GHz Quad-Core Processor ($329.89 @ OutletPC)
Motherboard: *Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard ($51.89 @ OutletPC)
Memory: *G.Skill NT Series 16GB (2 x 8GB) DDR4-2133 Memory ($59.49 @ Newegg)
Storage: *Sandisk Z400s 256GB 2.5" Solid State Drive ($71.99 @ NCIX US)
Video Card: EVGA GeForce GTX 960 2GB Superclocked Video Card ($184.99 @ SuperBiiz)
Case: *Xigmatek Spirit M MicroATX Mini Tower Case ($24.99 @ Newegg)
Power Supply: *EVGA 500W 80+ Bronze Certified ATX Power Supply ($43.57 @ Mac Mall)
Optical Drive: *Lite-On iHDS118-04 DVD/CD Drive ($12.89 @ OutletPC)
Operating System: *Microsoft Windows 10 Home OEM (64-bit) ($89.99 @ NCIX US)
Total: $869.69
Prices include shipping, taxes, and discounts when available
*Lowest price parts chosen from parametric criteria
Generated by PCPartPicker 2016-02-23 19:16 EST-0500

The second one I listed is basically an already cut down version of that.
If you don't know what overclocking is, don't worry about it, it's not necessary and more often than not just causes more problems for the inexperienced.

The K version is for overclocking, it's basically the same, but they changed a little bit of code that makes it easier to set it to higher Gigahertz. You also need a more expensive motherboard. The ram you listed isn't that much better than the one I listed, and it's price increase is roughly equivalent to how much better it is. The 4GB card will help with higher quality textures, but only on a select few games with really high quality texture options, and even though, your GPU isn't really powerful enough to run those types of games at higher settings anyways, hence why the i7 can be a downside.


I'll stress this again, the i7 doesn't really help with streaming all that much, it will help with video editing if you want to cut videos together for Youtube or whatever. The i5 can still do that, but just slower. If your time is so valuable that you need to do it faster (i.e. because it's your job) than the i7 is the smarter buy.

You can even stream with an i3 and 4GBs of ram if you really want to, you just have to make some minor quality tradeoffs.