I have both of these movies. Undead is amazing, made by the same brothers who created Day Breakers. I haven't seen many Australian zombie films, Undead could be the only one I know of. Back in the 60s the 70s and the 80s there was quite a bit of competition between the Italian and American film makers when it came to horror and zombie movies.
I've spent a lot of time watching these movies, I have Japanese, Chinese, Scottish, English, Australian, Sweedish, Mexican and yadda yadda yadda. To be honest, I think us in the good ol' USofA make the best zombie movies. We just have so many it's hard to compete.
When there is no more room in hell, the dead will walk the earth.