Stun Gun by decision. Silva is always a dangerous opponent, but I think Stun Gun can tire him out and effectively turn this into a grappling match.
Obviously a die hard Silva fan here but I don't disagree.
Honestly I think this fight comes down to when it ends. I can't see a way personally that Stun Gun finishes Silva... so basically, if the fight is stopped I think it will be Silva. If it goes for 15, I'd predict a judges nod for Kim.