hey mate.
i wouldn't worry about keeping the squid alive to much. If i downrig with 2 downriggers when i go out and one with a live squid and the other with a fresh caught dead one, the king hammer both at the same time. As long as its fresh and maintained well for that day, your won't have a problem. Also uses the snell rig like the other members have indicated, just try and cover most of the bait with the 2 hooks cause the kings sure get picky sometimes.