Are there different Apache distributions for different platforms?
Yes, or more accurately, different platforms package Apache differently.
And can I get it to have that?
Sure, add something like this to your Apache config:
Include /where/you/want/sites-enabled/
Can I use a2ensite and a2dissite without having that?
Those are just scripts built to handle adding and removing symlinks to sites-enabled
; they aren't included with your Mac install as they make no sense without a sites-enabled
type of setup. You can probably snag them and set them up on your system if you so choose, they'll probably need some tweaks.