It depends - Gsync does improve the quality a bit, especially any tearing/etc issues, but IMO it's a bit down the list in terms of what's best for a gaming monitor. Getting the size you want is probably the primary concern, the next is the hz rate - 144 to 165 is optimal, but if you go for a large 34/35+ gaming monitor, their 100hz work just fine - anything in triple digits is miles better than 60hz is the point. Next is the screen type, VA, TN, IPS - IPS in my opinion is the best balance of performance with visual appearance. If you're hardcore into FPS gaming, as in playing as a paid pro, then TN/VA may be better due to a bit faster performance, but that's so small that most of us, even competitive FPS players, shouldn't really care. IPS looks better in the vast majority of situations in games and in room lighting/etc, at least to me, and I've owned 1/2 dozen gsync performance monitors in the last year or two.
Gsync does have an effect, no doubt, and the thing is many of the decent quality gaming monitors already have the tech included. You can however find 24, 27, and larger sized monitors in both 1080p and 1440p in the 144hz range without it, there is a recent thread here IIRC with this exact spec monitor in it.
So, if you're going with a 1080 and want a gaming/high performance LCD monitor to match, decide which size, which resolution, and then come back and post that, and many here will give you options in terms of Gsync, hz rate, and type (VA/TN/IPS) to choose from. You do need to decide what size/res first though IMO, once that is narrowed down, it's easy to tighten the parameters and give you a good 3 or 4 options.
I primarily use Asus ROG Gsync 27" in 1440p, but I've had 4k Acer Gsyncs and Acer 27" IPS 1440P as well. The Gsync does have an effect, you don't appreciate it until you flip it off, and then you really can see the smoothing effect it has. It's just that there are other features IMO which have a great effect for the $, but if $ isn't a huge issue, then for sure, get an LCD with it.
Some simple options without knowing your pref - for $400 you can get a 24" AOC 1080p Gsync VA 144hz, a great option for this game, for $706 you can get an Acer Predator 27" Gsync 1440p IPS which IMO is one of the 2 best available options for gaming right now.
More here, Tom's 2017 best Gsync list -
http://www.tomshardware.com/reviews/best-gaming-monitors,4533-3.html