Using a Mac to make disk images?

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

I have some Apple II disks (including the ProDOS 4.02 system disk --
which is really the most important) that I need to make disk images of
on my PowerMac 9500 running MacOS 8.6.  What should I do to ensure that
I create valid disk images while not harming the actual disks?  Should
I boot my Mac with an earlier OS like 7.6?  Should I use DART, DiskCopy
4.2 or DiskCopy 6.x?  Thanks for the help, it is imperative that I make
images of these disks that will be able to create working Apple II
system disks in the future.