To mount the take-a-look on a helmet with visor, just clip it on the visor and re-bend it for the upside-down mounting. I used a small piece of duct tape to secure mine.

If you think that using a mirror is distracting, then you just haven't used a mirror enough. You should not have to make a special effort or even think about looking in the mirror; it should be just another part of your vision. You wouldn't wear blinders to keep from being "distracted" by your peripheral vision, would you? Does your peripheral vision "distract" you?

When I drive a car, I use all the mirrors, and I'm always 100% aware of every car that's close to me (at least 200 feet in crowded situations). You have to in order to do what my dad taught me which is to anticipate every stupid thing anyone around you might do, and to ALWAYS know where you can escape to if they do. You can't know whether it's safe to dodge right or left or slam on the brakes or speed up if you aren't fully aware of all the vehicles on all sides of you and whether they're going faster or slower than you or are changing lanes, etc.

If you aren't able to pay attention to that much stuff at once, then you need to practice.