it seems like the torque vs power thing confuses people a lot.
as others have already stated, torque and power aren't really two different measurements. they are mathematically related to each other, and that's why on all dyno graphs the torque and power curves cross at the same point.
maybe it would help those who find the theory hard to understand if we used some examples of how this all plays out.
take two motors that are both capable of producing the same amount of torque, but one revs higher than the other. the higher reving engine will have more power. even as you go past the torque peak, the power will continue to climb for a while because the extra revs make up for the lower torque. it's only after the torque starts to really drop off a lot that the extra revs don't help, and then the power drops off as well.
another way to think about it is this:
torque = how hard someone can punch you in the face
revs = how many times someone can punch you in the face in a minute
power = how beat up you are after a minute of taking punches
so if somebody can punch you really hard once or twice a minute, they will probably break your face less than someone who can punch a little less hard, but can do it 30 times a minute, but someone who can't punch hard at all can hit you as many times as they want and it wont hurt.
so coming back to gear ratios, it's power that counts, and you'll want to shift just before power starts to drop off, and your gears should be spaced so that you get enough revs in the next gear to keep the power up, which means you will never shift into a gear that puts you below the torque peak. (remember, you want a large number of medium hits, not a small number of hard hits)
hope that helps!