In a 75 gallon, either go for a smaller community of pisciovres
Oscars (2 with some smaller tankmates should be ok, though pushing the room factor)
Group of Nimbochromis (venustus, fusco, livingstonii)
Or just go out and get a 'glass banger' in that 75.
I would think Dovii would be too small (and probably too skittish by themselves, especially as grow outs).
Midas, Umbee (at least until it hits 12-14")
You may want to just get a community of smaller Centrals, maybe mixed with some africans:
Convicts, Salvinis, Firemouths, Electric Blue Hap, some mbunas, pair of Buffalo Heads.. - should give you some nice colors and loads of displays, as well as some fairly regular breeding.