EDIT: Disk issue is solved, using disk utility to make the iso instead of terminal ^^
I just setup sheep with MacOS 9.0.4 on Windows 8.1 64bit for the most part everything works perfectly, except for 2 things.
Mac CD-ROMs are unrecognized and want to be initialized. I tried an audio CD and it loaded in just fine. I also tried making an iso on an older Mac dekstop of the CD-ROM and loading that, but it also wanted to be initialized.
If I enable sound output the system freezes just after starting up. I tried removing the Apple Audio Extension, but that had no effect.
I'm not so certain about the sound, but I did find a workaround for the CD-ROMs (sort of). I used HxD to extract a CD-ROM's contents by opening the CD drive through HxD and saving the contents onto the hard drive. It seems a little excessive to use a hex editor, but that worked for me.
The CD-ROM driver to recognize Mac CDs is designed for 32-bit Windows systems, but not 64-bit ones. It would take a bit of time to get it fully working for 64-bit systems. There are third-party programs designed to read Mac CD-ROMs, but most of them need to be paid for in order to get rid of a time limit or allow full functionality.