First of all your friend is mixing two Coasts of Africa which is doable but I wouldn't recommend it. Melanochromis johannii
- Lake Malawi (East) Hemichromis guttatus
- aka. Jewel fish West Africa
As for as keeping african cichlids with plants, you have to decide which Coast you are going to keep in your setup. I wouldn't worry much about West African since those are very much doable. East African are little hard, especially Mbuna, but doable as well.
Here is my 75G tank with East African fauna from Lake Malawi and Tanganyika.
Visit my website to see longer description http://www.greenstouch.com/africanlakes.htm