I believe SA is producing CB A. nigripes.
IMO, there are several reason that they are not very popular.
1. They are found only in Sri Lanka and a couple other remote islands. There is not a lot of collecting there anymore. In the past the government has not been very stable. I don't know what it is like currently.
2. They are very poor shippers, so (like chrysopterus) wholesalers and retailers are not apt to bring them in because they are just throwing their money away.
3. Unlike you and I, most marine aquarium hobbyists don't find them that attractive and they stay in dealers tanks for a long time. Percs and ocellaris sell pretty easily (even the normal colored ones), other non-Nemo looking clowns don't generate as much interest.
I have a feeling that SA and whoever else might be producing them, likely won't be doing it for very long. It is pretty easy to flood the market with a fish like that. So, if you want them, you should probably get them now. I pretty much flooded my local market with only 2 batches of orange skunk clowns.