You know, after reading some of these posts, I realize that in retrospect, I'm glad the idea for the "remember" meld was added at the last minute. Because had it been planned out in advance, the obvious choice would have been Kirk, as noted above, not McCoy. A scene where Kirk starts to do the repair himself, Spock neck pinches him out of the way, melds with him, and then completes the repair.
However, because the meld was added at the last minute, and McCoy was in the scene, we got McCoy. And that added for some wonderful dramatic moments for De Kelley in the next film, as he confesses to the unconscious Spock how he feels about him.