For Java moss and Christmas moss, try aquabid.com. There are a number of online sellers that handle Java moss, and a few are starting to carry Christmas moss, as well. Fontinalis moss is also possible to find online, although I haven't yet seen 'mini' moss for sale.

Just to set the record straight! "Angel Moss" is actually Sphagnum Moss. It is Sphagnum Moss from New Zealand. I have seen where it grows and where they pick it from..... Definitely Sphagnum Moss. It's latin botanical name is "sphagnum christatum" & sometime they told me it has some 'sphagnum subnitens' (aprox 10%) mixed in with it as that is how it grows together. you can actually see the 2 different varieties once you know what to look for. It is a far cry from Chilean, Chinese & Peruvian moss in terms of quality...... New Zealand Sphagnum Moss isn't "picked by poor natives and sold as gold in western countries" The writer of this comment then suggests to use "Chinese moss" (Talk about poor natives). Obviously the writer of this comment has never done any investigative journalism and if he/she had toured NZ and seen the different Moss companies as I have, they wouldn't be so quick to pass a judgement on what the facts actually are. It is not a mixture of New Zealand, Chile & Peru moss as has been suggested. It is pure straight New Zealand Sphagnum Moss. As the company tells it, Angel Moss is just a brand name. (I guess kinda like Coke is one brand of the Coca Cola Company here in the US). New Zealand moss companies have been selling their Sphagnum Moss to Asian orchid growers, Bromeliad growers, Carnivorous plant growers etc. for 30+ years and it is known to be some of the best product out there. I'm guessing that's why it commands a higher price that other country's Sphagnum Moss. As far as the acidity of it goes I couldn't say exactly. but according to a test result on the Pacific Wide NZ Ltd website it is somewhere around 4.8. If that isn't acidic I don't know what is! I have tried to find information on growing Sphagnum Moss but there isn't much info out there and it is actually quite hard to do. If try and grow some and you feed the moss any type of fertilizer it seems to die, die, die! There is a .pdf document online I found someplace from a guy in England that grew some. but I forget where it is. I have it someplace. The Moss that you buy in store is dried so I don't think you'll propagate it at all. you need growing tips of the Sphagnum probably as it self propagates like this & some papers I've read says that it can propagate from it's seed pod thingy's they open up and kind of spray around like a kind of spore. I think sort of like mushrooms. I found the study that I did on Sphagnum Moss very fascinating and enjoyable..... It was quite a job to find all the facts and information on the subject. Simple.... Do your research People. or visit New Zealand moss companies like I have. they are very helpful and friendly. (incidentally it's a very nice country to vacation in by the way)

Thanks @tapla (mid-Michigan, USDA z5b-6a) for the clarification, very helpful as usual :) , thanks @floral_uk z.8/9 SW UK, here in Germany the products are labelled differently indeed, as far as I know, there is the "Gartentorf" which mixed peat with some soil to be acidic , and then there is the "Schwarzetorf" which translates to black/dark peat which comes from the deepest layer of the bog, then there is the "Weißtorf" which translates to white peat, although the color is light brown, this is the top layer of the bog, where you can still recognize some plants remains, labeled most of the time as soil aeration products, and finally there is the "Moostorf" which the the sphagnum peat Moss, it is the hardest to find here, mostly imported and expensive, I am still trying to get some peat Moss for a reasonable price, else I am considering the white/brown peat, which also has high water retaining properties but on the down side a very fine structure I was mainly wondering about the high acidity and whether the peat moss in north America is treated to be pH-neutral (those products are available online), but now this is clarified, the lime is added to the mix to increase pH in the 5:1:1 ! Thanks, Fahmy

Polyester foam is not likely to make a "good moisture holding substrate" for anything. It is hydrophobic. Also moss, IME, is very slow to bind to foam. Covering the foam with a thin layer of marine/aquarium grade silicone and then pressing in/impregnating the silicone with coir or chunky peat would help.