16mm is close to 5/8"
3/4" is as tall as risers can be when combined with Heli-bars, so you're good.
Or a 1.5" riser by itself(no Heli-bars).
You will need to remove a cable clamp.
Look in front of the gas tank on the frame, on the throttle side.
You'll see the clamp, and it's held in by one hex head bolt, 10mm head.
Just take the clamp off and put the bolt back, you'll never notice it gone.