https://gbatemp.net/threads/aureinand-n3ds-o3ds-a9lh.411110/That's the guide I followed except I went the Cakes route at the end. I don't see a lot information in the difference between Cakes and Aurei.
AuReiNAND has a lot of more features compared to Cakes. AuReiNAND even includes an integrated boot manager. It's also much safer than Cakes.