I've bought from CalWest too but it seems they've had a supply issue of late. WHen I needed it last time...they had none available. If they have it...they are also a good place to buy.
FWIW -- China also produces/grows a sphagnum moss. I suspect many of the asian growers are using the one from China rather than importing the NZ. I've never purchased it (to the best of my knowledge) but I hear it's a good quality sphag.