You can find course descriptions here:
http://www.collegeboard.com/student/testing/ap/sub_compscia.htmlhttp://www.collegeboard.com/student/testing/ap/sub_stats.htmlI have taken graduate level courses in mathematical statistics and I taught myself to program when I was 12.
Looking at the course descriptions, the AP Computer Science looks more appropriate for several reasons. The AP stats goes deeply into statistical nomenclature, but without the rigor of proofs, while the CS class looks more abstract but with a lot of hands-on work, so he will have the support of both the ideas and the work. This will give him an introduction into abstraction that the Stats class won't and then set him up to take more rigorous classes in CS or Math. And, CS should be fun, giving him more things to do with his computer.
After he is done with that year, I'd look at taking the following in priority at a community college: typing, C, and logic.
I assume he has taken Geometry? Has he read Euclid's Elements afterwards?
Calculus the next year is fine, but if he likes math, he should set his sights on taking more mathematically mature classes such as Real Analysis, Abstract Algebra, etc at a college. Even if he wants to do something else technical, he will have the time to become mathematically mature.
I helped a number of PHDs that did not have a mathy background and the stats they took set them up to fail because they did not have the deep understanding of what the math meant. For this reason, IMHO, I think he would appreciate stats more by taking a mathematical stats class that is very rigorous plus some actuarial classes - that are upper division or graduate level.
