Many thanks for all the input, exactly what I was looking for:
New thinking following suggestions:
12 no. Neon Tetra (have already)
3 no. Oto (have already)
12. no congo tetra,
2 no. dwarf gourami,
6 no. dwarf rainbowfish,
12 no. cherry barb,
2 no. assasin snail (have already)