Sell your old monitor and buy the one that you want, see how your SLI 980 Ti's handle the new monitor (res, refresh rate). If the GPU's don't perform up to your standards then get one of Nvidia's newer cards when they come out.

If you want to save some $$ on a CPU then sell your 6600K and get a used/new 6700K/7700K (you wouldn't need a new mobo) and you would get decent performance gains specially if you're aiming for a high refresh rate monitor. If you want to go to a new platform then just wait for Intel to release Cannon Lake, I believe?

Mainly for streaming I'd say go with a CPU like: R5 1600. If you can afford R7 1700 then get it, it will handle everything you throw at it and more.
Also get a 16GB RAM kit (2X8GB). The higher the frequency, the better (at least for Ryzen). Although I've noticed people with Ryzen builds often can't get their RAM to run higher than 2800mhz - 2933mhz. So don't over spend on something like a 3200mhz kit (you can always overclock your RAM or at least try). I personally have had good luck with overclocking DDR4 kits.
04dcarraher gave you a good recommendation. It's too bad GPU prices are so outrageous right now... GTX 1070 or even VEGA 56 would definitely accent R7 1700 & 16GB DDR4 nicely.

You're getting 140fps @ 1080p ULTRA? I get 100fps - 120fps @ 1440p ULTRA with my 6700K. The problem with 4 cores i5 & BF1 is that it only has 4 threads. I haven't played BF1 in a bit but from what I remember my 6700K stays around 65% - 70% load. There were tons of people that said i7 is a waste for gaming for quiet some years... although with new 6 cores i5 it's no longer a problem. i7's are great for high refresh rate monitors.

demi0227_basic: I don't think 1.264V is anything magical for 8700K @ 4.8GHz since it basically runs @ 4.7GHz out of the box. All you have to do is go into BIOS and set all cores multiplier to 47 (shouldn't even need any voltage adjustment). Newer chips are clocked higher out of the box while running @ 1.20V - 1.22V max. Still that's a big improvement over my 6700K which can only run @ 4.3GHz 1.250V, 4.4GHz 1.280V, 4.5GHz 1.310V Although I think that I got a chip that's not too happy about overclocking... But if I want to push 4.6GHz my voltage has to be set all the way to 1.340V - 1.350V (not worth it AT ALL honestly... this chip gets REALLY HOT above 1.31V) even with a decent cooler AIO w/ 240mm rad.

Try stress testing with Prime95 or OCCT and your temps will definitely get above 69C. What kinda cooler are you using?

That's why I was asking if there were any info. I know Volta has been on their map for quiet a while now.

Sold my 16GB Corsair Vengeance LPX 2400mhz (had it overclocked to 2800mhz) for nearly double of what I bought it for when I was building my Slylake rig. Purchased 16GB G.Skill Trident Z RGB 3000mhz. This RAM looks awesome in person. I haven't messed with ASUS Aura yet which apparently allows color changes.
Here are some shots.

Yeah I know that 1060 3GB is a bit of a better performer. But judging by those prices... I'd get 1050 Ti (that's my personal opinion though). I'd add the €105 left over towards the CPU which TC said he was in need of.

If that's the case then I'm gonna sit on my GTX 1080 for a lot longer than I anticipated. The card is beast @ 1440p as it is (right now). I haven't been keeping up with tech lately... can anyone link any info about it?

I haven't had any problems. I've used W10 Store quiet a bit this past week to re-download Forza Horizon 3, Forza Motorsport 7, Forza Hub, Gears 4 & Gears Ultimate Edition on to another HDD. Maybe some newer Windows Updates are giving you problems? You can try uninstalling recent updates.

Antivirus: ESET (NOD 32), CCleaner, Malwarebytes and recently got a pretty decent VPN service which has given me zero problems since I got it 3 months ago.

That's a tough choice... GTX 1060 3GB isn't really enough for 1080p now days.. I'm talking about VRAM... I'd honestly would probably get a 1050 Ti if I were you. It's a great budget GPU and it's 4GB afterall. Otherwise I would get GTX 1060 6GB.