Yea, your definetaly going to need more then a pair, more harder to breed species as they need hosts. Hap ahli's make good as ahli's breed like crazy and easily. Bigger tank better though like 55g or 75g. They will begin to spawn once the setting is right and as long as their other fish are breeding, the female will go and set eggs in the nest of fish's nest of eggs males fertilize them, the syno's hatch before the cichlid's eggs do and the syno babies eat the cichlid's eggs.
Some say blackworms is key to triggering them to spawn and keep them going...planetcatfish is prolly best way to go on more breeding tips.