If I was to set up that tank with Tangs, I'd go with a big school of Cyprichromis, a Neolamprologus (that will reproduce like crazy), a big school of Synodontis (multipunctatus, lucipinnis, etc.) and maybe a few calvus or something interesting looking. Love the idea of an mbu puffer or some other oddball to give it personality.
Even a big tank like that can be problematic as a New World tank, unless it's South Americans like Heros, Festivums, Geos and acaras (along with silver dollars, chalceus, etc.). A pair of Amphilophus or other big central americans could take over the whole tank if they decide to spawn. That's obviously not going to follow the plan of Texas Holey Rock and would be considerably more challenging with water quality, etc.
It's ideal for a Malawi tank.