Replying to Ski sizes and K2 PE vs. Armada ARV

Ok, im trying to decide on lengths of my new skis. The two skis im looking at are the NEw Public Enermys and the Armada ARVs. The lengths i would be looking at are in the K2s a 179 and i know i can hadle that but the closest size is eighter a 175 or 1 185 in the Armadas. I will mainly be useing the skis for backcountry and pow. But this dosent mean that i wont ever go into the park. Im leaning towards the ARV due to the fact the i will most likely be goin to Japan at the start of next year. Im around 166-170cm and im 70kg or 11stone. The ski choise will most likely be effected by the avalibility in Australia. Hope to hear some replys, Cheers Nick.