A simple Search does the magic:
http://youtube.com/watch?v=JQQttu_LHfEIt's a Let's Play, so you will hear commentary.
I might already say, the ending is exactly the same. With these exceptions.
When you defeat the first K.Rool, "Boss Boogie" continues to play while you're talking to Donkey and Diddy.
You don't get to see a characters parade.
The credits roll, in Donkey's tree-house, no Kiddy and Dixie in some weird rolling thingy, and the song "Credits" play.
In the second ending. The credits roll again when you defeat him, and the next thing is you go back to the Krematoa Map.
In the third ending, Banana Bird Queen's song is "Brothers Bear", there isn't any "Mama Bird" song in the GBA version.
The chase is shorter, and the song "Chase" used in Stampede Sprint is played. The next thing, the normal Ending appears, and the song is "Stilt Village".
I think the sprites used in the last ending are the same size the SNES version uses, since Kiddy's face surpasses the screen.
And no special Karate Moves from Cranky appear. The best ranks are not displayed in a TV, just normal letters with a different background according to your rank.
=)