I have been into African cichlids since 2006. And learned the hard way.
If you want your tank to have a good combo then you have to stick to their level of aggression: from mild to highly aggressive. The less aggressive species won't do well with the more aggressive types. Trust me, they won't breed, can't hold the eggs when they do. Hide all the time and are very timid when feeding time comes.
Size is another thing. Keep species all the same size roughly. Never have two of one species type either. Stick with one labidochromis, Psuedotropheus etc.. species per tank. Make sure to always have enough females for your males: 1 male to 3 females is good. Hybrids are a

in the African cichlid world.
Here's an article explaining more about why you should be careful what you choose.
http://www.cichlid-forum.com/articles/compatibility.php
http://www.malawicichlidhomepage.com...ibility_1.html