Are you guys serious? The chance of Conan ending up with either Haibara or Ayumi is and will alwayd be ZERO. ShinRan is the main canon pairing, ever since the first episode. Their relationship have been developing gradually. They both LOVE each other and share many similarities, like their sense of justice for example. Ayumi imitating Conan doesn't mean that they share anything common.
Seriously, stop making it seem like Conan-sama is a play boy because he's NOT. He only loves Ran and NO ONE else. No matter how much you jelly Conan and Haibara fan-made pairing fans wish that Ran will die, she won't =w= Even if we pretend she does, its not like Conan-sama will move on to Haibara =.="" He's loyal to Ran and isn't interested in any other girl. If he was (interested in other girls and not loyal to Ran), he would have been going out with Haibara right now right? Since he, as Shinichi, is currently absent from Ran, so even if she saw him as Conan with Haibara it won't really matter to her. Same goes for Ayumi. But no, Conan-sama loves Ran more that anyone else and is loyal to her, which is stated countless of times in the series. He WON'T move on to any other girl whether Ran is there at his side or not.
Case Closed.