Hey, I ended up with a planted tank so severums and Geophagus were out of the question (dig and eat plant). I decided to add 10 angelfish and they are faring well. I would say anything that is large enough that the bichir can’t get and also not anything with too much personality is okay. I am also considering adding a chocolate Ciclid and an indo tiger datnoid (i would need to upgrade my tank size and probably my get rid of the angelfish) but that would be somewhere in the future. Right now the angelfish don’t bother the bichir and the bichir doesn’t even attack the angels. They’ve laid eggs for me 3 times now and even got some fry from it! Good luck with your tank!