55 Gal for African Cichlids

[Mister Fish]

I have a 55 gal. tank that I want to set up for African Cichlids. First off I wanted to know what would be a healthy amount to keep in this size tank and what should I go with as far as gravel, coral etc, and what type of decorations should I put in the tank. I had mollies, platys, and tetras in the tank before I moved and I donated those to the daycare that my kids go to. Right now I have the Roman Empire theme going with 1 castle and a few pillars with some artificial trees. When it comes to the rocks how many pounds should I get? Any help would be great