Cichlids??? That is very vague. Lake Malawi cichlids are nice because they do BETTER when over stocked. I personally love a MALE peacock tank, all males or they can get aggressive. With proper filtration ( lots of it) you could have 100 safely.
Just look up Malawi peacock cichlids.
Other lake and river cichlids don't do quite as well in large numbers.
This tank is one I helped set up, and it will help give an idea on aquascaping. The trick "with malawi" is that they need areas, not homes. No holes or rock mounds that they can call there own. They NEED to be forced together and they will be happier, they are the one type of cichlid that does this