My interpretation is that the ability would trigger twice, but only on the original player that took the combat damage. It could not be copied to a second opponent. Does anyone have any additional info?
The copies will always affect the same player as the original ability.
Strionic Resonator would indeed copy Voks's ability because it's a triggered ability. It allows you to change the targets of the copied ability, but Mirko Vosk, Mind Drinker's ability does not contain the word "target", so you can't change anything about the copy.
706.10. To copy a spell, activated ability, or triggered ability means to put a copy of it onto the stack; a copy of a spell isn’t cast and a copy of an activated ability isn’t activated. A copy of a spell or ability copies both the characteristics of the spell or ability and all decisions made for it, including modes, targets, the value of X, and additional or alternative costs. [..]