There are believed to be at least 700 species of cichlids between the southern part of South America, ranging north to Texas. And between those areas are many climate zones, and varying types of water.
For a 60 gallon tank I would eliminate any that get larger than 6" as adults, so this nails down your choices to about 400 species.
The other criteria you may want to consider is the type tap water you have. Is it hard and laden with minerals?
Or is it soft.
If hard, and alkaline the Central Americans, and those South Americans from "west" of the Andes would be good choices.
If soft, the species from the Amazon, and equatorial areas in mid South America "east" of the Andes, may be more apropos.
If your tap water is neutral, neither soft nor hard, just about anything will work except the most sensitive species.
Will you prefer to use a heater or not, using room temp water?
If not, the species from Uruguay, Argentina and southern Brazil may be right for you, as would those from northern Mexico.
Some of those from northern South America need much warmer water than others.
If you could provide more details about your water parameters (provided to you on your water bill, by your water provider), a much more educated response could be given.