I haven't had to search for the items you need, however, I hope this might help.
Have you tried any of the following:
Riot (has brush on latex, don't know if this is what your after)
Clarks Rubber (has craft foam)
Bunnings/Mitre 10/ Home Hardware
I've heard it's hard to get wonderflex. I've have also heard that some cosplayers in Australia use Polymorph Pellets from Jaycar(but I don't know if they were successful)
Sorry I can't be more helpful or specific.