Your lighting will determine what kinds of plants you can have.
Not sure what plants are native to SE Asia but Anubias are good low light plants. They come in several varities. They don't get planted in gravel but attached to wood or rocks. The same for Java Fern and java moss.
Indian Almond Leaf - you most likely would need to get that from an ebay seller located in Asia. It does release tannins but it also turns the water amber colored - like in their natural habitat. I would do both floating and planted plants - dwarf lilly would be nice but it gets tall. I have to keep trimming the bigger leaf's off cause it blocks out too much light.
check out some of these - supposedly they are all low light