To make video stop automatically just double click on movie texture and uncheck "Looping". Some other interesting options include AutoPlay, Movie Stream Source and NeverStream. Not sure what Kismet node you were talking about, but there's New Action -> Cinematics -> Control Movie Texture, and it works flawlessly, you just have to supply it with a name of movie resource in Movie Texture field. Didn't try it with UIScenes yet..
The only problem i still see is that there's no way to know if movie has ended.. unless those two variables inside TextureMovie could help XD:
/** Whether the movie is currently paused. */
var const transient bool Paused;
/** Whether the movie is currently stopped. */
var const transient bool Stopped;