nap I'm not sure I understand your question or, even if, there's a question?!
As far as I'm aware, Debian does nor provide a default desktop set-up either, so you should most probably know what you need.
Personally, I don't use FreeBSD but, there're plenty of online resources covering the topic of installing a desktop on top of the base install. If you are after a simple window manager set-up, things are even simpler (or, not).
Would you care to explain a bit better what the question is?
Are you asking for a window manager recommendation? Preferences may vary and I don't think there's a right answer to that.