Mac's are cool. I like Mac, but they aren't for gaming.
They are for designer software, like Photoshop and business plans.
It's hard as hell to even hack a Mac.
Be happy they have a Mac client for people to play.
It's two different beasts. Tis why why it says "Windows PC" version of the game.
Mac don't have Windows unless you bootcamp or whatever you need to do with it.
I'd stick to what you got if you have the option here.