This is what I have, again from Europaspares. They have changed the mirror design slightly since I got this. The arm is adjustable for length. I reduced the length by about 2" in an effort to reduce the vibrations. Like all the mirrors they become a blurr as the engine does its job, OK at slow speeds. You have to remove the front bulkhead panel to get access to the underside for mounting bolts and I suggest a load spreading plate underneath.
Not quite as sophisticated, but been out about 3 years now and reasonable cost, as helmets go, tried one myself for a week and found it very good once you got used to it, however was not suitable in my case as most of my riding was with a pillion passenger, (don't tell SWMBO that her face kept upsetting me) http://www.reevu.com
Not sure what year a rear view mirror became compulsory, but mine wasn't made with one! I tried a couple of centre mirrors but neither worked in a vintage Morgan as the cockpit is small, you are close to the mirror - and with a passenger, you can't see anything!
So I've now got a side mounted mirror which you can see here:
After years of running up and down the country in assorted vans for the bike racing I really don't feel the need for a centre mirror. Of course using the same logic if I'd been driving BMWs then I wouldn't need mirrors at all!