Here is a basic template, page size is A4 landscape though, easy to change.
I've thrown in 4-dot-repeat mark symbols I created so you can copy them to other scores. There isn't (yet) a way to create new repeat barlines that act like the standard 2-dot ones, you just have to stick these symbols in the right place.
Let me know if you need it in a different sibelius version
Fynn