I stumbled back on to this post and thought I'd mention that I gave up on the idea of using pads as triggers. I took a gamble that I could learn to hit the SPD pads and it was a good decision. I probably hit them correctly about 95% of the time now :)
It would still be slick to have some kind of a bar that ran above the toms with several triggers on it. I am slightly tempted to take the SPD apart and see what they use as a triggering mechanism.