Can you give the foot print and other dimensions of the tank?
I am pretty sure Xenotilapia spiloptera and the similar Xenotilapia flavipinnis can work well as a species tank with dithers, in some 80 US g/300 liter tanks.
Maybe not like this article suggests with the other more territory grabbing species but not a fish to be scared of trying in a small tank.http://www.wetpetz.com/xenospilop.htm
I would suggest a better tank would be sticking to three Tang cichlids say.
Xenotilapia spiloptera or Xenotilapia flavipinnis group to get a pair or two and to provide dithers (mid water mainly)
Cyprichromis leptosoma group (mid to top water)
Eretmodus cyanostictus group of 6 to get a pair. (none territory holding bottom dwellers)
No idea about the other species you mention, not in my field.