Just about any well set-up brake should be able to put enough pressure on the rim with pretty limited hand force. The limit on braking force should really be where the rubber meets the road, not at the brake itself. In other words, you shouldn't have to go to the lengths you propose to get something that works for you. If your fingers are short, you may benefit from an adjustment of the reach of the brake, or even a smaller set of levers. I am 6'2" and can't quite palm a basketball, but I have wide palms and short fingers. On one of my bikes I switched my levers to smaller ones. That bike has bar-end shifters, though, so it was a pretty cheap fix.