I went through the same process in 2017 & 2018. I settled on the Acer 27" XFOH. Because it had zero frame (borderless), 1ms, Freesync, and 144hz refresh. It can scale to 1440p with my AMD RX580 card. SO I'm pretty sure the 2070 will do the trick as well. But I keep it locked at 1080p. I get ultra frames, and ultra smooth with enhanced sync (a Radeon Adrenalin 2019 setting) working alongside freesync. Frankly, I see zero difference with my setup using AMD's Virtual Super Resolution setting and 4K at 27".
I tested and demoed several kind of monitor sizes at home before finally settling on 27"-1080P. The 39"-43" 4ks were simply too big, slow and unenjoyable to my taste for a decent gaming PC. 34" was wonderful without the curve. But at the time...a great 1080p-1440p version was way too costly IMO. They may be better priced right now. But you'll notice the benefits of higher 144hz refresh rates of the 1080p models than any other feature IMO. You can get 120 HZ at 1440p on them (which is just as awesome). But the 4Ks only got 60Hz max when I was in the market. I found high refresh rates to be very noticeable if I didn't have it. But just part of the comfortable & flawless high end gaming experience when I engaged it. So in conclusion, I settled on the Acer 27" for my gaming rig. And an LG 43" model 6300U 4k UHDTV (in the same Media room) for console gaming with the XBox1X and Ninty Switch. I do have a high speed HDMI cable running from my RX580 to the LG UHDTV. But I never use it for PC gaming. 16+ms is just too much lag for my PC tastes. And 60hz or less refresh rates just don't cut it for me (except with console).