What else can I Stock with my Clown fish and Fire fish?

My tank is fully cycled, ammonia 0, nitrite 0, nitrate 3-5, pH 8.3, SG 1.023! 33 gallon aquarium. One ocellaris clown fish, one Fire fish and one zebra hermit crab. I was thinking about adding 2 Chromis but I hear they should be in groups of 6 or more and my tank is too small for 6 of them. What else can I put in with the stock I have now? I am a beginner at saltwater fish, so I ant something that is easy to care for and feed and isn't too expensive. PLEASE NO DAMSELS!