I think one of the Tunze Hydrofoamers should fit...I know they do on other INS models.
You can ask @rvitko here on R2R which unit would be the correct size for your skimmer.
You do have pump options!
That said, if you really do think about replacing the skimmer, a new Tunze 9415 or 9430 would be a pretty nice ride! I run the smaller 9410 on my 100 gallon system.