Too small for a colony of full sized corys really the pygmy cories would be better and corys should be kept in a group of 5+. Ghost shrimp is a generic name for FW, Brackish and Marine shrimp. Ask for the species name. If it is a macrobrachium sp. don't bother with them, Palaeomenetes can be kept but you need to research the species well estimate only 1-2 in that tank. If cardinia or neocardinia then they should be fine but again research the species a colony of 10+ would be good and purchasing off of ebay/aquabid or forum member would more then likely be cheaper then the store.