Join a local facebook group or become active with the Honolulu Aquarium Club. There are tons of local people who keep or have kept interesting things that I had never imagined here in the islands. Honestly, I'm not sure if you would otherwise get the proper response for a region-oriented question here on Fishlore. I've only seen a couple people from Hawaii on here, but they were mostly into freshwater. Well... there was one guy on Big Island who went from saltwater to freshwater, but idk what he kept.
One Spot Foxfaces and Foxface Lo are pretty common in the hobby. So I am sure an LFS can order one for you. That said, only a One Spot Foxface is suited to a 75 gallon and just barely at that. The Lo gets too big.