Considering you mention not having programmed extensively in a functional language, I'd say you should pick a language with extensive documentation for beginners. I know you dismissed it, but many people have put a lot of time and thought into designing materials for learning Haskell. In particular, I think most people recommend the Haskell book[1].

That being said, all the choices you list (Elm, Haskell, F#, OCaml, PureScript) are solid languages with good communities. The core languages are similar enough that if you start learning one, the things you learn will transfer decently enough to all the others.

[1]: Haskell Programming from First Principles (http://haskellbook.com/)