Hi Rocky! I have been fostering for several years & we use a combination of foods...
For hard food we mix together Purina One Kitten with IAMS kitten & Science Diet kitten - all poultry flavor and/or liver... The reason we use chicken based is because some kittens get a little upset tummy with seafood foods. It also cuts down on smelly poops. We use a combination so that when they are adopted their new owners have a choice without it upsetting their tummies.
For soft food we use Science Diet Kitten Chicken & Liver. Our little ones LOVE this & it seems to work with them when we are weaning. When weaning or when we have a sick baby we mix KMR with soft food - I have found this works well with the little ones.
One note, if your baby is not interested in eating food or seems to be a little lethargic (more than normal) they need to see a vet. Some bacterial infections can cause pain in their digestive tracts especially when eating. The one which we see alot around here is Feline Coccidia. Worms can also cause them distress. If Kelly's suggestions doesn't work, you may want to consult a vet about the babies possible issues.
Good luck with your little one!!!
#PetHealthandNutrition