I'm liking the mirrors I sourced from Spurcycle the last year or so. They have models for both drop and straight bars; one I have is for flat but it's working fine on the drops on my road bike. Theirs may not be as convex as you prefer though, I favor using mirrors just a little bit convex.

With my Varia or Carback giving me a sense of rearward traffic I find having a 'bar end mirror a comfortable alternative to turning my head far enough around to glimpse what's back their with my own eyes.

I've tried a few other brands, too often found the engineering or materials used for the mounts a bit of a disappointment.