Well, don't get oscars! lol.
Like I said, I have my carpintis in a 150. They are all fairly small.. 2 are about 7" and the others are like 4". I also have a marmokreb in there, a varigated shark, 2 parrots, and 3 honduran Jags I am growing out. Everyone gets along fine, but I'm sure that will change IF the jags pair off, which I am hoping they don't until I get my other 180 cleared out.
I went from 17 Frontosa, to 7... put them in with the rays, and they just started dying off (think they were biting ray tails) but anywho.. The colony that I do have left will be moving to a 180, and I am considering moving my SA/CA 180 tank into the 240.
I love SA/CA cichlids. They ALMOST trump my koi.
I think a Cuban pair would be cool as well, but they grow slow.