In order to help Doom-metal.com people you can send them a link or inof about the doom bands that you know near you area!
Alreday they have listed a lot of Chilean bands ( it seems that they have a huge scene there)
Personally, the best bands i have heard are Poema Arcanus and Mardegrises.
Mythological Cold Tower (brasil) are good, but i prefer the bands i've mention before.
I'm still in the process to digest the other bands. Silent Cry and My Threnody sounds a little goth to me, but still they are good bands!
And about Argentum, their "official" page used to work like 4 months ago, that was the place where i did found all the info aboout them, and i managed to get a Cd from them (Stigma Mortuorum). They disbanded like 3 years ago, and i think that other three releases. And looking for them, maybe Argentum is not 100% Doom but they do a good job, approaching to the genre!
If you're interested i can send you a copy of their album, let me know!
Doom On!