55 gallon tank stocking?

Mmk. What else, if anything can, do you suggest for my tank? Currently there are 8 orted danios, 2 pearl gouramis, 2 dwarf gouramis, and 4 black skirt tetras. Everyone gets along just dandy. Can come cory cats go in there? How many? And any other bright, but common because my pet store sucks, fish that would be okay in there?