Whipple will make a lot of instant power, Procharger has a more linear power curve, but because of that is a little easier on your drivetrain, and will make more top end power. It also weights a little less and the installation should be a little easier.
Pick your poison, they're both fun. I've owned both types of superchargers on a few different cars. Whipple is the more fun option (in terms of the wow factor when you mash the throttle), but if it's a daily driver that'll see rain and snow, a Procharger is the easier to drive/safer option.