What should I upgrade? Can my build handle a better monitor?

[brandonh6245]

I built my PC back in 2015 and now I think I might want to upgrade something, but I don't know what. Here is my current part list:
https://pcpartpicker.com/list/kQFfYr + https://goo.gl/a79GyQ (couldn't find the monitor on PC PartPicker). I want to upgrade to a 1440p 144hz monitor, and I think my current pc can handle that, but I'm not sure. (I play games like Rainbow Six Siege on max and I get 100+ frames currently.) Could I also use my current monitor as a second monitor, would it be able to handle that? I've been looking at this monitor: https://goo.gl/h7yofv. Basically, can I get good frames with a 1440p 140hz monitor with my current parts, and if not, what part(s) should I upgrade? Thanks for the help!

 

[Darkbreeze]

I would stick to 1080p with the R9 380. It can run 1440p but it will not do it at 144fps. Maybe at 30-60fps. If you want 1440p at 144fps you'll need a much more powerful card.

Unless you're willing to turn off a lot of the eye candy.

https://www.gamersnexus.net/hwreviews/1984-amd-r9-390-380-benchmark-review/Page-2