Vortex Viper or Burris Tac30 are in your price range. Both survive 3gun matches, so they are reasonably durable.
As for mount, you will need to raise the scope some to clear the front sight post so your cheek will need to be up a little.
The Vortex package you posted appears to be the magnifier and mount, not the actual scope. The Vortex Strikefire in the photo is another $170 or so. But it fits your needs.