Really it's a matter of personal preference as long as you stay away from the beddings known to be unsafe for snakes.

I have some of mine on newspaper, I have others on aspen. Sometimes I use packing paper I get from Home Depot. I have some snakes that consistently manage to spill their water dish so a loose bedding keeps it more firmly seated than paper would do. Other snakes I own seem to like to go under newspaper so that's what they get, others like to burrow in loose bedding - so they get aspen.

As long as you are happy and the snakes are happy - it's all good.