Galaxy is a now mostly discontinued malt that was developed to have very high levels of B-Glucanase so it could handle massive amounts of unmalted adjunct (say 40%+).
Unless you want to make something like one of the really pointless, undrinkable, thin as piss Asian style beers its a complete non event. From what I hear Commander isn't much better for all grain brewing, again designed for megs swill production, just with better growing and malting properties.
These days most of the Aussie big brewers use Sugar rather than cereal adjunct, its mostly for export.
So for the OP - forget it, just use any decent base malt, the recipe is using an Ale yeast (and a nice one) I would use Perle or Golden Promise as my first choices, but one of the decent Au/NZ base ale malts will get you there.
Mark