Hello and welcome to the forum!
Feel free to ask your questions in english - most of us will be able to read and reply in english
![Zwinkern ;)](./images/smilies/icon_e_wink.gif)
Here are some answers to your questions:
1. Even over here in Europe it is impossible to get about half of the Gonatodes species. There are a few G. daudini keepers and within the next years they will hopefully be available more often. The more common species (e.g. the ones from our care sheets) can be bought regularly and if you want to get shipped some to the States, just write me a PM.
2. You can use normal soil from the forest (no coniferous forest). We use sand from a river or sand for a childrens sand box. If you live near the ocean you can even use sand from the beach. Repti bark is also possible to use. But you would need a bigger layer so that it won´t get dry to early.
3. Unfortunately there aren´t much more infos about this wonderful genus. But feel free to ask your questions here and we hopefully can help you.
Greetings
Dennis