My suggestion is to look at images of PMC's and keep those images that you think are really cool. The thing with PMC's is that they are not regular military so each contractor will have his own set of rules (or no rules at all) for his group.
A quick search (see link) brings up a lot of pictures, this link is one I like and it reminds me of a Vietnam navy Seal. Notice the mix of civilian clothing with hi-end equipment and an AK. This guy is all ego. Probably ex special force. But you can narrow it down to baseball cap, Sunglasses, soft shell jacket or shirt, Condor light plate carrier and over the top weapons like the AK with a drum mag, no camo! If you look at yourself in your gear and think you could be regular military then (imho) your not doing it right for Airsoft