Not sure how many are in Australia, but you can safely add the SZD-59 to that list since it's pretty much a Jantar 3 as far as aerodynamics are concerned.

Same wing w/slightly larger ailerons and removable 1m tips (13.2m acro mode) and same fuselage but with the tailplane from the big Jantar, but in 15m it's essentially the same polar with a slight nod to the 48-3.

Discus seems strangely absent from that list.