I don't think it matters either way but I would start with whatever litter has been used by the breeder. I wouldn't use one that had a lot of dust and would want one that was okay if eaten by a curious kitten

 

I think non clumping is suggested for very young kittens as they tend to eat it but with an older kitten, either should be ok

 

Non clumping!

Kittens like to eat new interesting things, like litter. If they eat bits of clumping litter it could clump in their throats and choke them
I don't think it's as good for smells but just hang in there a while until the kitten is older (I waited about nine months). I think it says on packs not to use it for kittens. Not sure though but I seriously wouldn't risk it.

 

I've read that silica ones are the ones that shouldn't be used by kittens.