Im a little confused.You were going to get goldfish a coldwater species but have opted for warm water fish, do you have a heater in there? Also your tank looks vey coludy are you sure its cycled the whole way?

As for them being ok in a small tank, I find even the smallest cichlids get stressed in short tanks. It would defo be a good idea to go long for over your mantle, where you will be able to buy more and make them feel more comortable. They are lovely looking fish, even more so in a group.