MOTOSWAMI.......Here's a statistic that might mellow you re seeing behind. Over 75% of car/bike crashes are from the front and most are caused by left turning cars. Last I saw, crashes from the rear are less than 3%. Rather than spending on mirrors, you might want to get and install additional front lighting.
My two stock, non convex mirrors, set as wide as they can be, provide an extremely wide view of what's beside and behind me. Anything extra would be redundant. On the front of my bike are 6 lights (8 if you include the fender markers) 2 headlights, 2 fog/DRL lights, 2 3,000 lumen road lights - all LED.