Originally Posted by Acidictadpole
He's asking what the difference is so he can make the decision himself.
I don't personally know the difference, but this wikipedia article
may have what you're looking for.
Edit: from the article:
The c on the end may stand for compact, or the third iteration of the 32.
Most of these seem to be just different mag sizes, ammo types (moot in airsoft), and looks.
Pretty sure the 'C' is because the barrel is ported, helping control recoil.