Well, honestly I would go ahead and write it! From what I understand there were a hand[hoof]full of people who weren't satisfied with the ending (myself included)
While I personally don't think there's such a thing as a "bad" story, if it doesn't turn out the way you want it to, then at the very least you'll have more experience to write things in the future.
As for if it's already been written, I wouldn't worry to much about it. No two writers are exactly the same, and at the very least you'll provide a new interesting outlook on it.
So, yeah! Knock your socks off! I, for one, look forward to reading it if you decide you want to write it. Cheers!