Have you looked at Pseudotropheus Saulosi? Don't put with demasoni but if you sell they'll do we'll. females are beautiful yellow orange and males transform to blue black. I wouldn't mix labidochromis together as they may hybridize but if you have a large group of each then could be ok. Look at chisumulae (clown labs) and exasperatus. Maingano are nice, pseudo Polit are nice, metriaclima pulpican. And there's tons of different cynotilapia that are awesome. This page has info on all of them.
Cichlid Profiles