Sourcing appropriate sound accompaniment for a video production.

For some of the film I added some ambiance in post production to give an icy/unsettling atmosphere to the shots and scenes. It of course is not copyright and is free background music. Originally i was going to use some ominous synths for the background but choose to have a lack of music to add a tense feeling.
https://www.youtube.com/watch?v=1nD3Sp_saz4
For some scenes I used thunder and rain sound effects too add the real sense of them being in a remote isolated place. I also used the video to have lightning flashes in one scene.
https://www.youtube.com/watch?v=gVKEM4K8J8A