Cories like to be in groups of at least 4. I suggest you add 2 more. Angels are a possibility BTW. So are pearl gouramies. Silver sharks need a 125 gallon tank so they are out of the question - they get to 12" and are schooling fish. About those 'small fish' you haven't identified, I suggest you try to figure out what they are as this might effect your stocking. I personaly think they could be harlquin rasboras or checkered barbs. Either way, you nee to ensure that, if like harlequins and barbs, they are schooling fish, that they are in a group of at least 5-6. You must also determine whther they are fin-nippers. As for the pairs of cichlids. If they breed, they will become aggressive but I think the 2 you have selected could be kept together in your tank. (angels are also cichlids BTW...)