I didn't find any sources for moss spores in my books, but a Google search for Moss spores did turn up a few sources, mostly for Bonsai, as well as the buttermilk formula and more advice on growing them-- all apparently outdoors.

It also dawned on me that the Club mosses, Selaginella sp. (not a true moss, but something in between a fern and a moss in appearance, do well in tropical vivariums. The S. krausianna brownii pictured stays pretty low, but I doubt that's what you are looking for.

-----
Patty
Pahsimeroi, Idaho

D. auratus blue, auratus Ancon Hill, galactonotus orange, galactonotus yellow, fantasticus, reticulatus, imitator, castaneoticus, azureus, pumilio Bastimentos. P. lugubris, vittatus, terribilis mint green, terribilis orange.