I feed my bichirs a 50% diet of "clean" feeders that I breed. But in your case I do not recommend giving our fish "dirty" feeders. but if can't find any other food (which I think you can) I would rather get the mosquito fish ( the one in the lower picture) rather than the goldfish since the goldfish have thiaminease ( an enzyme that breaks down thiamine ,also known as Vitamin B). Before you feed the feeders make sure to gut load them with healthy food (floating pellets bloodworms and etc)