Sigma SD1 Merrill has a Sigma SA Bayonet lens mount and currently there are 77 native lenses available for this mount.
The latest released lenses that are compatible with the SD1 Merrill are the Sigma 12-24mm F4.5-5.6 EX DG HSM, the Sigma 20mm F1.8 EX DG RF and the Sigma 24mm F1.8 EX DG.
Sigma SD1 Merrill doesn't have a sensor based image stabilization system but
29 of these lenses already comes with optical image stabilization.
Since Sigma SD1 Merrill has a APS-C sensor, it has a focal length multiplier of 1.5× 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 SD1 Merrill.
You may also also be interested in these:
Sigma SD1 Merrill Lenses with Image Stabilization
Sigma SD1 Merrill Lenses with Weather Sealings