I've been using the Drunk Elephant Vitamin C serum. I mix it in with Paula's Choice omega + serum, hyaluronic acid, and facial oil, which probably helps to buffer it a little bit. My skin is not as sensitive as yours, though, I don't think. I started by trying it in one of the little holiday duos DE put out and it didn't irritate my skin, unlike the Paula's Choice one I tried.
My skin is somewhat sensitive (turns red easily). I use Drunk Elephant and mix it with Drunk Elephant B-Hydra serum and have had no issues with irritation. I've also put it on without mixing and haven't had issues.