Anubias and moss (maybe java fern or bolbitis?) are probably a good start. Pretty tough plants, tolerant of all kinds of plant-unfriendly conditions, and they don't need substrate - you can grow them on rocks, driftwood, whatever.
I think some of the bigger cichlids can be fairly rough on plants, but I don't have the personal experience. Maybe some sub-surface floaters like guppy grass, hornwort, etc.?