1080p can be fine on larger screens incl monis, the important part is how far away you sit from it.
using it closer than 3ft you might be able to see a "screen" door effect (larger pixels than the "optimum" size of 24" for 1080p res).
but as long as your further away and its fine.
i used a 27" (passive 3D) for about a year, and only when i was 2ft (or closer) did i notice the pixels when displaying text.
I'm planning to have my RX 480 in crossfire configuration.
going 144hz, as mentioned before, is a waste of money unless you plan on playing FPS and you want either smoother gameplay (from higher frame rate) or reduce input lag, but will cost a lot more gpu power and unless your running something like a 1080Ti, most games will be bottlenecked by the cpu (at 1080p).
whats your budged and where can you get stuff from, might be able to find a decent 1440p screen.
https://pcpartpicker.com/product/YZn2FT/benq-monitor-gw2765ht
the asus is virtually the same screen, but higher max refresh (75hz), better calibrated out of box, and one of the best non-pro screens on the market.
https://pcpartpicker.com/product/7TrcCJ/asus-pb277q-270-75hz-monitor-pb277q