/Quote where is the best place to get kickstart disks? /quote
You can only get Kickstart Disks for the A1000 and only Kickstart Versions 1.0, 1.1, 1.2 and 1.3 are available.
For the A600 you will need to get a new Kickstart ROM Chip.
The A600 will use A500 ROMs but then the Special Onboard IDE devices will not be configured.
Sorry never had, used or repaired an A600.
It think it's the only CBM produced Amiga Mode I never worked with.
Cheers
Shaf