stay with your current firmware, mine is XXUBMI7 and bought outright from samsung store.
-I well aware that EU Phone has Region Locked, this concern me not to flash any other stock firmware from differrent region unless officially release from Samsung Australia.
-Play safe and be patient about region lock.
Samsung Galaxy S3 White 32gb GT9300 Neatrom Lite V4.5 + Stock Kernel + 32GB Samsung Class 10 Plus
Samsung Galaxy S2 White 16gb GT9100T NeatRom Lite V4.8 + Philz 5.10.0 + 32GB Samsung Class 10 Plus (Give away for Relative)
Nexus 7 Gen II 32gb
Samsung Galaxy Note 3 White SM-N9005 32gb Stock 4.3 XXUBMI7 Samsung 64gb SDXC Pro