1 point slings are good for cqb because you can literally drop your primary to switch to a pistol. But the rifle now is hanging and dangling so it may become annoying..
2 point slings are great for outdoor games, they keep the gun where you put it, not as quick as a 1 point sling to transition to your secondary..
I'd get a 2 point sling, just because you can convert it to a single point, while you can't convert a 1 point to a 2 point..
MS3 replicas are decent, had mine for more than 2 years and it's still in great shape