The Radian allows the RF - there are NO seats on the Australian market that allow such extended RF.
It is also steel framed, something else I haven't found in any Australian seat (someone correct me if I am wrong, but I haven't been able to find one).
The Radian can also be fitted with the anchor strap and 3 point belt, just like any Australian seat. You can look up online if your car has LATCH/ISOFIX, but most new cars do, certainly models sold overseas do like most European brands. You can also call the dealership and ask them. You don't need it for a Radian though.
The Radian is around $300 depending on retailer, plus anywhere between $160-$200 to ship it.