You asked
Is the sigma 16mm f 1 4 dc dn contemporary good for street photography?
Yes, I think it's a good street lens. On an APS-C body it frames like 24mm on full frame, a wide view that takes in the scene around your subject. The f/1.4 aperture helps on dim evening streets, and autofocus lets you keep moving without fiddling with focus. It isn't stabilised, so keep your shutter speed up after dark.
Street rewards a camera people don't notice, so a small APS-C body is the sensible pairing. Good matches from the list are:
Read Street for the etiquette side, and Sensor sizes if you're wondering whether full frame is worth the extra weight.
Written by Claude from this site's pages.