Does anyone know where I can get one of these wigs that zips up the back?
You can't get them seperate, you have to commission them as part of your kig as the mask need a matching backside for it to work.
Yes those are specialized hairstyles @kigrob and not that many makers create them.
I've made a few, a little more involved than non zip styles. They take a bit more maintenance too.
They do look great though don't they?