Okay, then...allow me to respond TO THE ACTUAL QUESTION...jeez...
Seydaman, there's a ton of different styles and price ranges on what constitutes a "trench coat". If you want the look of someone who could blend in with the Wall Street types, any kind of London Fog coat would suffice; those are the types with the three large buttons down one side, and almost always come with a belt(see that picture of Rorschach). If you're looking for more of a "bad-ass" style, you'll want something called a Reverend's/Preacher's Coat (hey, I don't name 'em, I'm just a fan.) These are the style that tend to hug close on the shoulders and through the trunk, flaring out at the hips, almost like bell bottoms-for an example of that, done well, check out the coat Ashe Corven wears in the second Crow movie. There are also dusters and riding coats, but if you want quality out of one of those, you're going to have to get a Jacaru or a Drizzabone which can be a little pricey, but are definitely worth it.