Liz--
I don't think you will find the statistics you seek. (But I would be happy to be proven wrong, and would love to know about it if so.) I have been looking for the same thing for a while now. I have a public health background and know a bit about the way statistical studies get constructed, and AN surgery isn't easy to draw statistical conclusions from. The main reasons for this seem to be two interrelated things:
1) AN surgery outcomes are influenced by a fantastic number of variables (size of tumor, location, personal anatomy, surgical skill, experience, acts of god), many of which we really don't understand, and
2) ANs are rare, so the raw number of "data points" is pretty low.
These problems compound each other. A small number of ANs to start, then a smaller number that are in location X, and an even smaller number in people with your set of symptoms, and so on... pretty soon you're talking about only a few thousand people "like you" on which we could base a medical study... than reduce that number to those who go to a particular surgical center, or a particular surgeon, and the numbers are so small that you can't really trust them statistically.
So, what I've decided is best for me personally, is to look at the overall statistics for AN surgeries and use them to plan/prepare and ask questions... but in choosing a surgeon, I'm going with experience and qualitative recommendations as my influencing factors.
And on House/local options... it sounds to me that you can get good care locally -- just choose someone experienced.
Feel free to PM me with questions, and good luck.