I like to plan ahead. I am planning my stock list for my 37 and have a question (obviously). I plan on having 5 fish, blk/white clown, royal gramma (is this pronounced like grandma btw?), neon blue goby, pj cardinal. What would be better to have, 2 of the clowns or 2 of the pj cardinals? It seems that the tank would not be big enough for 2 of each and my son is SET on the gramma and goby... Thanks guys!