@liuzhouI think of peanut butter and peanut sauce as very different critters. Peanut butter should be as simple as possible: ground up peanuts. Jif and Skippy, the two most widely used peanut butters in America, are highly processed and full of sugar. Most of us grew up on them in PB & J sandwiches. For that classic I prefer a more natural brand with no sugar added, like Adams. I'm not so into it that I am willing to grind my own nuts, although that can be wonderful.
Perhaps I am culturally off base ur just of limited experience, but I think of peanut sauce as a more complex sauce for Chinese noodles or dipping sauce for certain--mostly Asian--snacking items. But for an easy hack in making Asian style peanut sauce I'm very happy with Jade brand All Natural Sichuan Peanut Sauce. It has heat and flavor. There are plenty of other peanut-based sauce products out there on store shelves, but I'm not wild about the other ones I've tasted.
I didn't mean to dis the use of peanut butter as an ingredient in making sauces. I'm sure there's no end to the variety of sauces that can be whipped up by a talented cook; it's just one of those things I don't tackle. Hope this makes sense.