I would go with large smooth pond rocks on one half of the tank and leave the sand on the other half. Then you can put some fake plants in there embeded into the rocks so that when your cichlids get bigger they won't be able to pull them out(if they can they will). Then throw some pieces of drift wood in there and you're set. This way the fish have a nice habitat and can still dig in the sand like they will eventually love to do. Have of your tank will also be nice and wide open so that you can see the fish well but they will still have some where to get away when they need to. This setup is very similar to how I have my Oscar tank set up right now and she loves it!!!!