You asked
Olympus pen e pl7 vs panasonic lumix gh4?
The Olympus PEN E-PL7 and the Panasonic Lumix GH4 both use the same Micro Four Thirds sensor, with a 2.0 crop factor, so they take the same lenses. The E-PL7 has stabilisation built into the body and a flip-down selfie screen. The GH4 has no body stabilisation, so pair it with a stabilised lens such as the Olympus M.Zuiko 12-100mm f/4 IS PRO. It was also the camera that brought 4K video to Micro Four Thirds.
For an everyday kit on either body, I'd start with the Olympus M.Zuiko 12-45mm f/4 PRO and add the Olympus M.Zuiko 25mm f/1.8 for low light.
Written by Claude from this site's pages.