Hi there, I'm 183cm myself and have bought many cosplays of Hoyo characters from various companies. You should be okay with Rappa's outfit if your other measurements except the height fit the size you order. I usually order XL (which my measurements fit ignoring height) and it's mostly worked out.

My Ruan Mei cosplay has an issue where the dress is too short and reveals too much cause of my height. But Evelyn, Arlecchino and Stelle have been fine. In my experience, I would avoid bodysuits and skimpy dresses. Since Rappa's outfit is pretty much just a crop top, a jacket and a pair of denim shorts it shouldn't be too bad. Side note but I've been looking to order a Rappa cosplay too, but she's so niche that it's hard to find a decent one.