When my cats were kittens, I fed:
Wet food- Wellness complete health Kitten formula, Instinct Kitten, and Fancy Feast kitten variety pack.
Dry food- Instinct Kitten.
I'm always switching out the rotation when it comes around to ordering more food. The current rotation consists of:
Wellness-Turkey, Chicken & Herring, Turkey & Salmon and Chicken
Merrick- Duck, Turkey and Chicken
Halo- Chicken Stew and Turkey & Giblets
Miko- Variety Packs from chewy
Landmark-...
I don't know if you've already got a heating pad or what not, but i highly recommend the snuggle safe pet bed heating pad!!
I used it a couple years ago with kittens i found and it worked great!!