I'm interested in getting either M. ramirezi or M. altispinosa to go along with my 2 black Tetra, 6 gold Tetras, 4 Otocinclus and 1 Bristlenose in a 55 gal. tank. Can anyone tell me the difference between the 2 microgeophagus and which is easier to keep? How many will fit comfortably in the tank without overcrowding?

Thanks