Cant wait until you set this up! Im currently keeping a small Tanginikan set up and have kept lots of species specific shelldwellers in the past--occies being my favorite because they can get so pretty and are so pugnacious. Great personality. But i agree with what's been said--not a good idea with the calvus/comps. Im keeping Gold Heads right now who are new to me but continue to hear and read they cant get along with the Shellie's since they roam in the same part of tank, and eat up all the fry with those long snouts of theirs. (And you are bound to get fry if you keep Shellie's, lol.) I just introduced a group of great looking Julidochromis marlieri and love them. They move around the tank in such a cool way. So far everyone is respecting each other's space but I know I will have to move some Julies out once a pair forms.
Question: have you though of keeping a school of leptosoma? I think they would love such a large tank.
Good luck.