You asked
Sony e 16mm f 2 8 vs sirui sniper 16mm f 1 2?
The Sony E 16mm f/2.8 is the small, simple choice. It's a pancake wide-angle for APS-C Sony E bodies, and it frames like 24mm on full frame with the depth of field of about f/4.2.
The Sirui Sniper 16mm f/1.2 is my pick if you shoot in low light or want more background blur. It has the same 24mm-equivalent view, but f/1.2 gives about the depth of field of f/1.8. It also comes in Fujifilm X and Nikon Z mounts, so it's the better buy if you might switch systems.
Neither lens is stabilised, and both autofocus. If you're on Sony E and mostly shoot in daylight, the Sony is the easy, sensible option. If you want the fastest wide view you can get on APS-C, get the Sirui. For how aperture changes depth of field across sensor sizes, see the focal length converter.
Written by Claude from this site's pages.