Panasonic has really good image stabilization for MFT systems where lens stabilization and sensor stabilization system work in tandem allowing to take shots with up to 1 second exposure handheld. Basically it's like having gimble inside the camera.

Panasonic 25mm f/1.7 (50mm f/3.5 equivalent full frame) is under $200 and is an excellent portrait lens.

With initial release of GH5 autofocus was pretty bad, but with the last firmware upgrade apparently it's quite good now.

I however cant yet justify upgrade from GH4, which doesn't have sensor stabilization.