Personally, I rather see what Canales can do with a new QB and DC before pulling the trigger.
If he is really hell bent on bringing the old "Seattle" days with him, hire someone that was apart of the Legion of Boom. I could see someone like Kris Richard coming here (currently Jacksonville's DB coach) to be the DC.
As for QB, I have no clue who Canales would bring in if Young is gone. Obviously the most familiar name to him would be Russell Wilson or maybe Drew Lock as a bridge QB and then maybe draft one to sit behind him.