I wouldn't bother with the Minoura handlebar-mount; it looks very similar to the Minoura handlebar bottle-cage mount which can unexpectedly shift when carrying an approximate cameraworth of weight of water.
I'm very bad at not stopping and taking pictures these days but am trying to change this by keeping the camera out of the pannier in a shoulder-strapped Crumpler (Ben's Pizza XL - stores a DSLR and up to three smallish (i.e. prime) lenses - bought in 2003 but modern equivalents exist) which I prevent from swinging round to the front (as would otherwise always happen with my riding position/back shape) with a hooked bungee cord, attached to a belt-loop:
It stretches round enough to retrieve the camera without having to unhook the hook and doesn't usually result in skewed shorts (and, so far, no ripped belt loops).
The only way of getting decent quick-reaction shots is to sling it round your neck and shoulder on a decent strap at a length where it's just long enough to swing forward under your armpit and up to your eye. I used to use a padded Calumet strap but reverted to the simple strap which came with the camera as it meant two fewer snap-buckles to potentially fail or snap unexpectedly open at an unfortunate moment.