I like the idea of the africans. I'd go with a male peacock tank of several species, you'll get some great colors.
Here's a bit of a starter list, you'll have to adjust for what you can find for sale.
Aulonocara German Red
Aulonocara maulana
Protomelas Stevani
Aulonocara Rubescens Ruby Red
Aulonocara maylandia
Aulonocara stuartgranti (usisya, ngara, cobue)
Aulonocara lwanda
Copadichromis trewavasae