In regards to cable replacement, I wrote with the seller on eBay (the same linked to earlier in this thread).
He said the cable for the momentum and HD5xx does not fit Aurvana Live 2 due to the lock-mechanism. Someone here already purchased the HD5xx cable and it seemed to work just fine (I guess the seller just assumed), someone did though mention its very long headphone connector that might cause some strain (page 22).
Anyway, the seller said to get these instead: http://www.ebay.com/itm/NEW-Replacement-upgrade-Cable-For-AKG-Y45BT-Y50-Y40-Y55-K845BT-K840KL-headphones-/201195269395?rd=1 - also has a shorter connector.
Last but not least he said it was copper.
edit: this is the cable another user bought that worked (with the long connector): http://www.ebay.com/itm/NEW-Replacement-Audio-upgrade-Cable-For-Sennheiser-HD598-HD558-HD518-Headphone-/261255113290?pt=US_MP3_Player_Cables_Adapters&var=&hash=item3cd404aa4a&rmvSB=true
Oh, and seller said they put $8 on packages (value), so customs shouldnt be an issue. ;)
Edited by Juusuhako - 1/24/15 at 11:19am