Let me say this once and for all.
Mac OS 7.5.3 is NOT released under the GNU!
It has, however, been released as freeware by Apple. If you want a link, I'll give you one.
Running Mac OS X natively on a beige box, which I THINK you're asking advice about, is ILLEGAL, and discussion of HOW to do it will not be permitted here. However, if you want to do it via emulation, that's just fine.