Both Cameras are good enough to do this...
These are more of a Semi-Professional grade camera...
My recommendation is not in the camera itself, but rather in your choice of Lens.
Autofocus is quicker on a lower focal length lens, a 14mm on the Lumix, or a 16mm on the NEX combined with the High Megapixels of the Cameras, and you can easily crop your photos, to see the detail for prints or Posting on the Internet.
The other feature both of these cameras offer, is the option to get out of AUTOMATIC MODE, and use APERTURE PRIORITY mode... (Av) doing this will tell the camera, that you want the the picture a certain Brightness... and it will listen.
Setting your ISO to AUTO, and the focus drive to continuous, and you should end up with WAAAAY more "keepers" than you ever thought Possible.
