First, do not get the Celsius S36. The Dark Rock 3 I suggested will be quieter. If you're determined to get an AIO, get a 280mm AIO. Kraken X62 is a popular option(and a great one), but it's pretty expensive at $150. So, for a nice 280mm AIO around the same price as the S36, you can get the Kraken X61, which although it's the older brother of the X62, is still a great cooler. Alternatively, you'll see Corsair H110i's go on sale for $100, for that price they're a steal, but for $120, you're better off just getting an X61. I'd still recommend the Dark Rock 3 over any of these, only reason to go with the AIO is for aesthetics.
Next, on to RAM.
Z06 wroteMemory: Corsair - Dominator Platinum 32GB (4 x 8GB) DDR4-3333 Memory ($387.99 @ Amazon)
This is just a huge waste of money for literally no reason.
As I said, 32GB RAM is unnecessary. However, if you were to go with 32GB, you can easily get a 32GB kit for less than $300.
For HDD's, do NOT buy a WD Black. Don't buy 2 x 3TB Barracuda's either. You can get a 5TB HDD for $140, or 6TB for $160-170. Again, seriously consider this before wasting money. 2TB is more than enough for the vast majority of people, so wasting money on a large HDD is just utterly pointless. Especially considering you can grab a 2TB HDD, or even 3TB if you really want right now for a decent price, and then in the future, if you really need more storage, you can easily add more.
Also, with a $2700-3700 budget, I wouldn't get the MX300. I'd just spend the premium for the 850 EVO. The MX300 is great, but it still comes 2nd to the 850 EVO. I also wouldn't get the 2TB 850 EVO though, grab a 500GB 850 EVO or a 1TB 850 EVO.
Case wise, Enthoo Pro M and Meshify C are both good. I'd take the Meshify C over the Enthoo Pro M just because it's a little nicer IMO, and a little bit better build quality, but not really noticeably better so the Enthoo Pro M is perfectly adequate if that's your preference.
Absolutely zero reason to buy a 1000W PSU, it's stupid and a huge waste of money. 8700k and GTX 1080Ti overclocked as far as you can get them won't even pull 400W.
For monitor, I'd really recommend getting the ultrawide. However, if you're set on a pair of 16:9's for whatever reason, do not get a 4k monitor and then a completely different 1080p monitor from a different company. I'd suggest getting 2 of the same 1440p or 4k monitors, you have the budget for it. Otherwise, at least get an LG 4K and LG 1080p monitor. Also, avoid 1080p at 27", it looks shit. Anything larger than 24" at 1080p is a no go.
The Corsair K70 is a better quality keyboard than the KM780. It's also cheaper. There is no reason to buy the KM780. That Razer mouse is overpriced for what it is. I wouldn't bother. Razer mice aren't actually bad, at least for the most part, but they are all overpriced.
So, here you go;
PCPartPicker part list / Price breakdown by merchant
CPU: Intel - Core i7-8700K 3.7GHz 6-Core Processor ($399.89 @ B&H)
CPU Cooler: NZXT - Kraken X62 Rev 2 98.2 CFM Liquid CPU Cooler ($154.79 @ SuperBiiz)
Motherboard: Gigabyte - Z370 AORUS Gaming 7 (rev. 1.0) ATX LGA1151 Motherboard ($253.98 @ Newegg)
Memory: Corsair - Vengeance LPX 32GB (2 x 16GB) DDR4-3000 Memory ($289.00 @ Amazon)
Storage: Samsung - 850 EVO-Series 1TB 2.5" Solid State Drive ($327.99 @ Amazon)
Storage: Toshiba - X300 5TB 3.5" 7200RPM Internal Hard Drive ($141.95 @ Amazon)
Video Card: EVGA - GeForce GTX 1080 Ti 11GB SC Black Edition Video Card ($744.99 @ Amazon)
Case: Fractal Design - Meshify C ATX Mid Tower Case ($89.99 @ SuperBiiz)
Power Supply: EVGA - SuperNOVA G3 850W 80+ Gold Certified Fully-Modular ATX Power Supply ($109.99 @ Amazon)
Keyboard: Corsair - K70 LUX RGB Wired Gaming Keyboard ($129.99 @ Amazon)
Mouse: Corsair - M65 PRO RGB FPS Wired Optical Mouse ($47.99 @ Amazon)
and again, SERIOUSLY consider the 5/6TB HDD, it's likely unnecessary. Also seriously consider the 32GB RAM, it's definitely unnecessary. I've included the X62 here, because it's the most expensive cooler you should consider, but again, X61 if you want a cheaper AIO, or Dark Rock 3 for better acoustics. I've also included the Meshify C, because it's what I'd get but again, swap for the Enthoo Pro M if you want.
I have not included monitors here, so you'll need to use your $1000 remaining budget for those. Like I said, I'd recommend the ultrawide I already linked above, here it is again;
Otherwise, get 2 of these 4k monitors;
or 2 of these 1440p monitors;
*Edit* I've just realised I've completely missed case fans in this entire thread, get Be Quiet! Pure Wings 2's, or SilentWings 3's.