From what I read off of other boards(planted tank, aquaticplantcentral) that you can keep anubias, moss, and ferns in there. Anything that will attach itself to rock then your good. The main plants I think would be Anubias since it will look good with Africans due to the fact its from africa lol. Just make sure it is attached to the rock or in a secure place before adding the mbuna. They will nibble on it, no doubt about that.
The same will go for the Cons but you also have more room to grow because you can add some stem plants if you bury the stems deep enough. Either way leaves will be nibbled on. Let us know what you decide.
^I agree with Katie. 8 Cons, not good. I would say 4 but that still might be pucshing it but Im not an expert!