Food suggestions for syno cats.

[Eupterus]

I'm browsing around for a new staple food for my synos.
Preferably something in 1/2- 1 lb size to make shipping worthwhile, pellets/larger sticks, sinking and not primarily made of slaughterhouse by products or ocean fish.

[Lupin]

Sera O-nip tablets? I don't see your reason for being choosy with foods. Anything is fine.