Panasonic GH5S has a Micro Four Thirds lens mount and currently there are 90 native lenses available for this mount.
Panasonic GH5S doesn't have a sensor based image stabilization system but 22 of these lenses already comes with optical image stabilization.
Since Panasonic GH5S has a Four Thirds sensor, it has a focal length multiplier of 2x so you have to multiply lenses original focal length with this multiplier to find the Full Frame equivalent focal length of the lens when mounted on GH5S.
You may also also be interested in these:
Panasonic GH5S Lenses with Image Stabilization
Panasonic GH5S Lenses with Weather Sealings