Wow, so many mouths to feed! If you are looking for a bit higher quality pellet food instead of the flakes, you can try Hai Feng foods, they come in all kinds of varieties - wheat germ, color enhancers, growth food,.....
I am sure Hai Feng has its own website, but thats all I came up with right now....
http://www.champkoi.com/food/hai_feng.htmlA lot of pond fish keepers swear by that food, and I feed it to mine as well....