Sorry to leave you guys hanging. Centropyge abei was very recently described from one specimen and a few sightings around 120m in Sulawesi. It has been seen before, from a submersible and the video is really cool. This species is probably more widespread, but is usually found below 500ft which is really the limit that we can push our rebreathers to. I would not be suprised if it is shallower, say 100m, at other localities.
I have never seen Genicanthus semicinctus in the wild, but I have seen Genicanthus spinus at Rapa Iti in French Polynesia.
Aloha,
Brian