Hi Soneca, I am also a Brazilian starting two very modest side business intending to sell to international customers:
What a coincidence, huh?
In the beginning I also considered Atlas, but that seemed way too much trouble and expenses for two businesses that may or may not be viable.
In the end, I decided to go with Paddle (https://paddle.com/). The integration was really easy, it is just a button that links to my subscription plans (with webhooks that alert my server when subscriptions are created and paid).
As Brazilians say, we should "exchange stickers".