I'm buying the GH3. Having used APS-C for forever, I need some lens recommendations, primarily for travel, so it needs to be light and minimal. I'm thinking about: Ultrawide - but I need one that can take a variable ND filter. How can this be accomplished with m4/3? Superzoom - Panasonic 14-140mm f/4.0-5.8 ASPH./MEGA O.I.S. Lumix G Vario HD Prime - Panasonic 20mm f/1.7 Aspheric G- Series Pancake Lens (46mm) Any input?