Here are two bootable CP/M System disk images for the Commodore 128.  One image is a .d64 and will need to be used with a 1571 floppy drive (won't work with a 1541) and the other is a .d81 for use with a 1581 floppy drive.  Although the screen shots show this as CP/M 3.0, it is interesting to note that there is actually no such thing, and this is actually CP/M Plus 3.1.  If you're interested in details about this and CP/M history, check out this link over at H2Obsession.  For other CP/M System disks, check out the Zimmer File Archive.