I may be hostile, but at least I don't make embarrassing mistakes when I point things out.
This quote is off of the page you linked to. "Having kept a number of chocolate cichlids I can happily recommend this cichlid to anyone who is interested in keeping a 4×18x18 tank with something quite different."
You said your tank was only a 60 gallon. I guess you don't have enough space after all, at least not according to the site you are choosing to believe.
Looking around on the internet and taking all that is seen into consideration is a good plan. Looking for a plan that fits yours, might not be the best idea.
Here's another recommendation of the same size as your link.
75 gallons
http://www.aquariumlife.net/profiles/south-american-cichlid/chocolate-cichlid/100154.asp
There are many other sites that recommend only a 55 gallon tank. The real problem with them is that the tank is only 12" front to back and a chocolate cichlid is 12" long. Bad plan. The generic plan for a fish tank is for it to be 4 times as long as the adult size of your fish, so in this case 4', and 1.5 times as wide as your your fish is long at its adult size, again in this case 18" wide.
If your tank meets those requirements and only holds 60 gallons of water it must be only 16" deep, apparently either your tank is NOT big enough, or is a custom built tank with really strange dimensions. I love the fact that the very web site you have chose to "back up your argument" proves you incorrect.