I use bed-a-beast or eco earth (both are coconut fiber). And if you are going to use KK (I used/use them also) just go though the sizes as he/she grows. If you start off with a sling then even the smallest KK will be too big. They are semi aboreal so you would not stand a KK on it's end like you would do with an Avic.
Ok. Yea I wouldn't put it in the KK right away.. The one I'm probably getting is already 1.5 inches. So probably start him in a deli cup?
1 Ultramel Stripe Corn: Pyro
1 Normal Corn: Hypno
1 Normal Ball Python: Bubba
1 Spider Ball Python: Spiderman
1 Red Tail Boa: Zero
3 Bearded Dragons: Tweak, Puff, and Kimbo
2 Leopard Geckos: Gizmo and Geek
3 African Fat Tail Geckos: Oreo, Comet, and Jaws
2 Green Iguanas: Rex and Frogger
1 Fat Rat (Not food): Marshmellow
3 Red Eared Sliders: Donatello, Michealangelo, Raphael