I use vermiculite in containers with eggs that I put in my incubator but use spagnum moss as a substrate in the nesting boxes.
bunnings sells it in usually small 5 litre bags and is the fine grade 1.
I buy my vermiculite in Sydney from Ausperl - Australian Perlite Ltd in 100 litre bags grade 4 for about $20 a bag. they also have perlite.