Well... IF you partition your Hard Drive, that means that you erase eeevery single thing, then you go and make partitions using apple's Drive Setup. There you can format one partition to be an a/UX partition (UNIX partition) and the rest you can format to be HFS+, so you dont really need to worry if OS X can be installed on a UNIX partition.
FYI --> OS X can be installed on a unix formated HD, but I dont think that classic will work.
Admiral