According to the interwebs, Copy II Mac does bit-level copying.  It will even copy disks that have bad sectors.

To save as a disk image, you have to use Copy II Hard Disk.  I'm gonna snag a copy and try it out.  I have a couple games that didn't want to copy using Disk Copy 4.2 (would get a read error at the end), but I could copy them manually.  I wonder if they had copy protection.