Hello

I don't owned acf's but I think that a big piece of driftwood(no sharp hedges) always look great as a center piece, you could tied anubias on it, you would not need co2 for anubias, they are slow growing plants. I know that acfs are rough on plants, they uproot plants so I am not sure what other kinds of plants would be good, maybe a few tall or/and floating silk plants on the back and corners and a few caves would look great