i don't think you should put any new species in that tank until you get all your schools rounded out. I don't know much about some of these fish, but I know they all like groups.
3 Australian Rainbow Fish
2 Dwarf Sunset Platies
1 Yo Yo Loach
3-5 Kuhilli Loach
5 Cherry Barbs
1-3 Otto
1-3 Peppered Cories
3 Glow Light Tetra
i don't know the sizes on some of these fish, but you may have a full stock (inch wise) before you complete your shoals.