Here's how you make a "Four Chick Ghostbusters" movie work. Sigourney Weaver reprises her role and somehow discovers some evil supernatural plot but can't get the original team back together for various reasons. Having more knowledge about this shit than your average person, she recruits some relative no-names to join her. I'm talking no one even close to the star level of all the chicks listed previously (yes, even Anna Farris). People like, but not limited to, Mary Death from Bounty Killer of course (Christian Pitre), since she's my avatar. The kryptonian badass from Man of Steel, Antje Traue. And then maybe someone like Lyndsy Fonseca (Nikita, Kickass). Maybe a fourth if you want Sigourney to just have a small supervisory role.
That's the only way I see an all-female team working, because the moment you put four high-profile female actors together like has been suggested, it is practically bound to fail. Sure, there's a chance it could succeed, but none of us believe it. But put Sigourney in to sort of transition things and then get three or four actresses who are hungry to make a bigger name for themselves, and MAYBE a movie like this has a chance.
I mean, I'd rather it never happen just like most of you, but if it has to happen, forget the A-listers. Saves money as well as drama.