Did you ever see Devils Brigade? That is one of the best ever.
As far as your two selections, may I suggest renting "Tour of Duty". It dates back to 1987, but is fairly accurate tactically (taking into account they have to get their bodies and faces in the screen), and the story lines are sometimes corny, but season three picks up a lot as they begin working with MACV SOG.
Nope, I haven't seen Devils Brigade. What's it about and when was it made?
I do remember watching and liking the Tour of Duty series.