ive been researching alot about fish sizes and tank sizes in the past couple of days because im trying to build myself a beautiful tank for the type of fish i want and from what you have explained, id have to say that it would be a good size if you only have 2 and it also depends on how much decorations you have in the tank as well. basically the bigger the fish can get, the bigger the tank you will need and the number of fish you have also determines the size as well. from my research, a good tank size would have to be a 55 gal that way your fish have all the space they need