I’d go with a sleep sack; you’ll get the most use out of it. Swaddles aren’t safe after baby attempts to roll or after 8 weeks. Blankets are never safe

Swaddle! Get the Velcro swaddles, they’re great. No blankets.

I have always used the brand “love to dream” swaddles with all my kids they’re great!

I did swaddles when my son was born

I was always taught that newborns should never sleep with a blanket or anything else in the bassinet or crib. I’d suggest looking at safe sleep options such as swaddles and sleep sacks.