The Be Quiet Silent Base 801 is a crucial part of this build, along with the Be Quiet 280mm AIO water cooler. https://www.youtube.com/watch?v=pf_ejKGzd9c
What you do is you mount the radiator in the front with 4 140mm Be Quiet push/pull fans. You'll have tons of cooling for your CPU with zero noise. https://www.youtube.com/watch?v=YCZ5iP5cu8g
Then you go with the RTX 2080 Seahawk X. This thing runs dead silent at full load (but you'll need to replace the noisy stock fan that the 120mm radiator comes with). You'll be able to game at 1080p on the highest possible settings and clear 100-120+ frames guaranteed. That's really all you need. With G Sync on and setting NVidia profiler to a 120 fps limit, you're all set. You can just abuse the hell out of this system and it'll never fail to deliver a quality experience (for an excellent price too).
And, if that's not enough, you got a 2TB m.2 raid 0, and the whole package is less expensive than Zotac's most expensive MEK Ultra: https://www.amazon.com/ZOTAC-GeForce-Liquid-Cooled-i9-7900X-System-GU208TS901B-U-W2B/dp/B07JJBJPP3
One complaint I do have, after having built this thing, is that the shipping times on the be quiet! brand parts are atrocious (took me about a month from when I placed the order). You should seriously consider using something like a Fractal Design Meshify C with Noctua fans. The fan technology is really important, as there are newer, more expensive fans on the market that DRASTICALLY reduce noise. Noctua and be quiet! are the best brands.
I also have some additional advice I learned from what went wrong with my previous computer. I had a $2500+ gaming rig that was acting like it couldn't handle Dungeon Siege 3. This was mostly because my fans were absolutely horrible in terms of noise. But also my entire installation of Windows 10 was totally crapping out on me. The only way to successfully fix my Windows 10 installation was to completely start over from scratch (was that messed up- all kinds of glitches and freezing that I learned to live with for 3 years). So, that's my advice- don't underestimate the power of getting the latest technology in low decibel fans (pure wings 3 high rpm 140mm x2 for your Corsair AIO water cooler for instance). Also I highly recommend NOT using an SLI setup. It's SUCH a pain to constantly be second guessing whether or not the SLI is even functioning properly. It's just not worth the hassle at all, trust me.
Go with the newest generation CPU/GPU if you can afford it obviously. But for the rest of the build you REALLY need to take a good hard look at what the best fans are, and to make sure your Windows 10 isn't crashing when it hibernates or sleeps. My 2080 isn't the TI version, but I would rather have better thermal efficiency than squeezing out those extra frames. That's also why I would never overclock my CPU. The i9 9900K turbo boosts to 4.7 GHz on its own just fine.
Anyways, my first test was to play Dungeon Siege 3 at the highest settings I could. No noise (because I was using silent wings 3 fans). But also- no heat. My graphics card runs cold with no heat build up, and my CPU wouldn't go above 47 degrees. My CPU's AIO liquid cooling radiator wasn't struggling in the slightest bit. It was practically idling.
So, as far as I can tell, this build is a mission accomplished. Any time I want to, I can crank my settings to maximum and just forget about all the worry and the obnoxious noises coming from my tower case. I have absolute confidence that my system can try its hardest without scaring me into thinking it's coughing up a lung. And maybe in 3 years, since I saved 700 dollars by not using the TI, I can just replace my graphics card with something better. No big deal.
It's the noise-driven stress that ruins the gaming computer experience for me. So, I'm definitely satisfied with how this is panning out. And this build wasn't that difficult either. I went extremely slow with it (because I sort of forgot how to do it), but honestly anybody can do it. The worst parts are the radiator fan screws and reading the motherboard instructions to find the correct pin holes for the tower case. Also I must've taken nearly an hour to realize that the legs to the tower case were hidden in one of the two giant styrofoam pieces of all places.