A 25 gallon is small for a cichlid tank unless you want to have dwarf cichlids. A good choice is blue rams. You could keep other fish in with them as well. My best advice is to look around online to research the species you may want to keep and also ask questions.
Do you know why your fish are not lasting long? If you don't, please feel free to ask questions. Often it's just a matter of working out the problem and you'll be addicted to your fish after that.