Imaging floppies on a Mac?

[bvito <bvito@ne.mediaone.net>]

I have recently purchased a ProDOS 4.0.2 3.5" system disk, and I would
like to back it up as a disk image on my Mac, so that I can create a
new one at any time should I mess it up in any way.  How should I go
about this?  Should I use DiskCopy 4.2, 6.3.3, or DART?  And do I need
to boot my PowerMac 9500 with an older system version than 8.6?  Like
7.6?  Thanks for the help, I need to be sure that I don't destroy my
new system disk in the process and that the image I make will be able
to create working, bootable disks.  thanks.