2-3 inch tetras

Hello! My friend gave me a 10 gallon tank with a rainbow shark, i learned they need bigger tanks and im purchasing a 75 gallon tank this weekend ! I currently have two plattys, two bleeding heart tetras, a black molly , and a Dalmatian molly in the tank with the rainbow shark , they all get...

Looking for species that 1. only get between 2-3 inches 2. are pretty colorful 3. are taller bodied (like serpae, black skirt, or columbian) 4. school together 5. aren't too aggressive 6. are fast swimmers google didn't really help me with my search for this.