I'm sorry, I have absolutely no idea if this helps. She asked for a body proportions and poses guide and I was going to draw bases, but I thought this might be more helpful because it's more universal.
What I got from this was Danny Fenton has a rectangular torso while Danny Phantom has a trapezoidal torso that tapers into his waist. His legs are a lot skinnier than his human side, too, probably because of his tight spandex suit.
It really hope this helps!
Oh, and did you want a female one as well?