Ok?
My advice to you is make your own characters. It let's you expand your mind so nobody will say "You had a fact wrong". Another thing, I strongly recommend using an M14 as jungle/urban combat can have a problem with a bolt action rifle. And one last thing, Use a Huey helicopter and make your charachter jump off the heli while the heli is 5-10 feet of the ground so it makes it more realistic. By that i mean, Who the hell wants a helicopter in mid air for 20 in enemy territory, no one. And correct me if im wrong, I might be thinging of another guy but i heard a sniper killed a Vietcong General and he crawled for days, got lots of ant bites and was dropped off on a ridge and not in the middle of the jungle.