North Vietnamese regular army. Well equipped by its Chinese and Russian allies, they also fight fiercely, supported sometimes by air and armor.
http://i.imgur.com/n3uget3.jpg. Weapons used:
Chances to have grenades: 20% to have 1-3 grenades
Chances to have American weaponry: 0%
Chances to have Support Weapons 5% per men deployed
Chances to yield intel 25%