try using abalone shells,they look cool and they are perfect for cichlid breeding.also you could try those big barnacle looking shell things,my dad said his cons used it as a favorite breeding spot
that one pic looked like a male lombardio and if it is you are in for a nasty tank
the convicts are nasty at breeding time but a male lombardio at more than 5" is a ticking time bomb they get nasty fast and can kill almost any other cichlid that gets in there way