Honestly, Halloween is in a more..problematic area now, as an IP for Universal to use.
The only films that they can truly use, is Halloween 2 & Season of The Witch. And they just did 2 with 2016.
Outside of that, there isn't exactly anywhere else unless you want to get more legal and complicated.
I think Purge has a better shot than The Shape, but that can honestly change within the minute depending on how Halloween (2018)'s sequel is being developed.