Most new release amiibo since Smash Ultimate launch haven't been too difficult to get, normally can wait and get a discount, but just a heads up preorders are starting since I think Joker will likely be popular.
Gamesmen/Amazon doesn't seem to be available just yet while Target and Big W will have to wait until launch day.
Can't wait to get both amiibos, but I gotta ask my wife's boyfriend's permission first before preordering!