C and Python are the languages in which I've done most of my work (I'm still a student). In fact I didn't look to see how's FP done in those languages with which I'm most familiar and that does sound like good advice. Thanks!
1. It is very easy to set up a batteries included development environment.
2. The community is dedicated to teaching students functional programming principles.
3. The Racket ecosystem provides tools for learning other programming paradigms including: lazy, statically typed, declarative, reactive, meta-programming, etc.
4. The sweet spot of Clojure is professional developers. There is often an assumption of foundational knowledge of the JVM [or Javscript in the case of Clojurescript].
5. The sweet spot of Haskell is programmers with a strong computer science background. The literature and discussion tends to be more toward the academic journal paper end of the spectrum.
Good luck.