i agree with mike--go either with haps/peacocks OR mbuna. i dont think both would work in a 125 gallon..
the peacocks and haps would be more appealing to the eye, and offer more color and a range of sizes. im not a huge fan of demasonis--ive had a large school of them in the past (in a 90gal), and they were so aggressive they sacrificed eachother until i had just a few left--then they turned on the labs i had and terrorized them.
then again, you could just take what i say with a grain of salt seeing i have 3 tanks full of mbuna lol..