Dacort has put out a huge line of unique figures mostly all based around his unique Natalia mesh, also has coforming mermaid and snake tails for Victoria, Michael and Stephanie. In freestuff you'll find a p4 female based mermaid and seanymph, a'lite' version of Undine which is a Natalia-based stand alone figure...some clothing for her as well.

The free Maya Doll is available at Studio Maya's Maya Doll downloads page, scroll down to find latest mesh updates, hair and clothing.

Vina/Dina was made by Dacort/DSI...she's available at Renderotica(be warned, adult site)and I believe Animotions, a more comic book oriented poser site...no where near as many freebies out for her as Victoria, but she's another unique mesh you might consider looking into.