I have seen dried Destroying Angels being sold online on at least one occasion, but it would be irresponsible of me to share.
You should definitely NOT try to CTB using deadly mushrooms. Although several Amanita species are capable of killing you, the actual severity and consistency of their effect is often extremely overstated.
No two functional mushrooms contain the same amount of the desired toxin (or hallucinogen) so appropriately dosing wild mushrooms is actually exceedingly difficult.
People survive consuming amanita verna all the time. Although death IS very probable when intentionally ingesting a large amount of them, the death you'd suffer would likely be slow and painful. Steady organ shutdown is not a nice way to go.