profjiang8,
I have a MacBook Air that is running Win 8.1 via Boot Camp. If your Mac has comparable specs to the PC specs Jimbuna posted, you shouldn't have any problems.
I went for 50 GB for the Boot Camp partition, but after installing the OS, various Windows updates, SH4 and mods, wish I had a bit more.
Also take a look at this
thread for general installation tips.
Good luck!