I don't know sh*t about hot sauces, but several of my friends are really into them, they make their own and test what they can get. And all of them recommend this one:
https://heatonist.com/hot-ones-hot-sauce/
If it's half as good as the youtube show the producers of this sauce have, where they interview various celebrities over hot wings with sauces that go up to 2 mil scoville, and that's supposedly a lot. (check it out:
https://www.youtube.com/watch?v=7TN09IP5JuI)