I seen one installed a few weeks ago, it was copper. The cabinet had a board over the cabinet doors to support the front. The back was glued to the bottom side of the granite countertop. Seems like it could have had support on the sides but I'am not sure.
I'm not sure what you mean by an apron front. I presume you mean the ones where the front does come down below the countertop? If you are talking about a new one then I don't know. The older cast iron ones would have a bracket on the back for the ledge backs and the rims are self rimming. Is this a new sink?