The whole linchpin of this is to have the most realistic copy of a firearm as possible. Getting that in your hands and then showing up in the woods with a G-Unit loadout isn't going to make the impression you're hoping for.
Once you're part of the scene (it doesn't take long for that to happen either) then you can workup oddball rigs like a video game character or urban terrorist.
We have a local guy in OD army surplus and black boots and he's very effective.
Airsoft, where nothing is hurt but feelings.