While I could hear "I haven't decided yet" in Garak's voice, and this is very funny, I don't think it fits with in-universe Garak. He's not a psychopath killing people at random — he had specific reasons to kill the people he did, and generally with surgical precision. I can't see him planning to just kill someone for no particular reason.
(sorry for being that guy and criticising a joke)
(I still upvoted!)