Could be worth seeing if there's a local sling library that you can try out different ones at.
If you have a sling library near you then go and try some different ones on to see which suits you best. I have an eegobaby omni 360 breeze and love it but everyone is different.
We have the infantino carrier which is a really reasonable price and our LO is very happy in there 🙂
@Claire second this. My LO sleeps so well in it
If you have the budget, I definitely recommend the Babybjorn Mesh Harmony - you can find some discounts and get cashback, possibly second hand too if you wanted. Has great lumbar support, really easy to use, and lasts until they're 3 years old. I've definitely been so glad I opted for it! Also super easy to clean. ☺️