I know two. One is called Atty and one is just called Atticus. It sounds classic (as in ancient Rome and also as in classic books because of TKAM). I can't imagine a little kid pulling it off but it's the kind of name you'd grow into.
Personally I think Kit is too much of a stretch (it's taking the "tic" part of Atticus and then switching the consonant sounds?) but I would find it interesting if I met one.