Sigma fp has a Leica L lens mount and currently there are 146 native lenses available for this mount.
The latest released lenses that are compatible with the fp are the SG-image AF 35mm f2.2, the 7Artisans 135mm f1.8 L and the TTArtisan 50mm f1.8 NEO L.
Sigma fp doesn't have a sensor based image stabilization system but
17 of these lenses already comes with optical image stabilization.
Since Sigma fp has a Full frame sensor, it has a focal length multiplier of 1x 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 fp.
You may also also be interested in these:
Sigma fp Lenses with Image Stabilization
Sigma fp Lenses with Weather Sealings