I'm with Hogleg.
Poblanos: 1,000-2,000 Scoville Heat Units.
Serranos: 10,000-25,000.
Habanero: 150,000-325,000
Thai: 50,000-100,000
While you COULD just blend them all together into a sauce, why not make a few different sauces with different flavor profiles and heat levels? Examples:
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