Any of the other larger botiine loaches will do fine. I would say the blue botia/Redtail Botia/Red-finned Loach (Yasuhikotakia modesta and sometimes Botia modesta) would be best. The ladder loach (Botia rostrata), yoyo loach (Botia almorhae), Bengal loach (Botia dario) are some that don't get nearly as large as the clowns but are large enough to not be seen as food. They would also add some variety.One more question;
What other loaches go well with Clowns?