It completely comes down to BUDGET. The card can even handle a 4K, 60Hz monitor but that's almost certainly too costly.
A 1080p, 60Hz monitor is fairly cheap though I recommend at least the following:
a) IPS (not TN), and
b) 6ms or lower response time
c) 22" to 24"
144Hz has its pros and cons. Mainly you likely can't output 144FPS in most games, at all times, so you'd likely want to disable VSYNC. That causes screen tearing, however that's less likely to be obvious on a high refresh monitor (with lower FPS values). The higher the Hz/FPS ratio the less obvious the tears are.
In some games you can enable Adaptive VSYNC (half refresh) which should cap to 72FPS VSYNC ON (but disable VSYNC below 72FPS). On a 144Hz monitor I'd use that...