I've just started using an amby baby hammock (for approx 1 week now.) as DS#2 has really bad wind and so far he seems to be sleeping better and isn't waking up screaming like he was when he was in his bassinet which I used for the first 2 weeks

they say you can use them for approx birth - 12 months depending on baby weight and length
the amby hammocks cost approx $300+ but you can also hire hammocks as a cheaper option, so it may be worth a look

good luck