Since you are speaking about Central Americans, and their water parameters are generally hard, and high pH, to me they are basic geographically appropriate choices that fit the mold.
Lives bearers based upon size
https://hosting.photobucket.com/alb...s49523db1.jpg?width=320&height=320&fit=bounds,
https://hosting.photobucket.com/alb...sffcd4588.jpg?width=320&height=320&fit=bounds
Above are sail fin mollies that can reach 7", or smaller live bearers such as Xiphorous only fitting with smaller cichlidshttps://hosting.photobucket.com/albums/i97/dstuer/zoogono/swordtails/.highres/IMG_7177_zps7e769668.jpg?width=320&height=320&fit=bounds,
https://hosting.photobucket.com/alb...s0evb8wjn.jpg?width=320&height=320&fit=bounds
Or size appropriate, and water parameters appropriate Characins
Above are Tetras of the genus Roeboides, I've had success with cichlids up to the 7" range, in pH 8+ water parameters.
Below Astyanax , and Brycon Tetras
Keeping any with piscavores like Parachromis, would seem to be an exercise in futility though.
Below are Curmatid (tootjless tetras) found all over Central America in high pH water
Where I find them, they usually outnumber cichids by 40 or 50 to 1.