Action shots for 4/3 camera

I've been posting through forums about the best mirror less camera for action shots. I've looked at NEX and nikon's, both seem to have their downfalls when it comes to this category. How are the 4/3's cameras with this type of shooting. How are the video capabilities as well. The specific sport I will be shooting is KITEBOARDING. What cameras and lenses do you recommend? and how do they compare to the fore mentioned cameras. I currently use a sony a57 but i need something more lightweight that I can carry anywhere with me. In terms of my research here the panasonic gx1 catches my eye. Thanks in advance for the help!