WTF? If you need a quick shifter to alleviate stress on your left hand while doing longer rides... you really need to hang up your keys and sell your bikes. They're a track orientated option, plain and simple.
It's not a big deal at all to simply roll off the throttle for a half second, click the shifter into a higher gear (*WITHOUT* pulling in the clutch) and away you go back on the gas.
If you can't do that without a quick shifter, you need to evaluate your riding skills and take some courses to improve them.
I'm curious though -- can you please explain to me how you find pulling a clutch lever on the highway once or twice an hour more tiring than controlling your throttle for the same amount of time?
You mentioned touring as the primary reason for needing one -- isn't most touring done on highways? Why would you need a quick shifter there? Makes about as much sense as wearing mukluks in the high desert.