Here's a different consideration. Your 600 and 1200 are both of more recent surface mount construction. So are the 4000 and CD32. They are working now, but, if a chip goes bad, most likely you will have to find someone to repair the motherboard, if you can.
OTOH, the 1000, 500, 2000 and 3000 (CDTV, too?) are the older thru-hole and socket construction. If a chip in one of those takes a dive, it is far easier to replace. Swapping chips is even a useful troubleshooting technique. There is plenty of documentation. IMHO, the 2000s and 3000s with RTG can do some fairly modern things. A500s are still plentiful and dirt cheap (though starting to demand rising prices).
So, how long do you want to be an Amigan?
EDIT: I've often wondered if the early SCSI HDs have better longevity going forward than newer IDE and solid state solutions.