What you're trying to do is similar to asking 100 mulit-millionaires to donate all their wealth to charity. it's physically possible, but economically impossible. this is the whole genius of the system. if 51% of the hashing power stays honest, the system works. the reason why people don't destroy the network out of self-interest, is that they can't profitable do so. to move to another algorithm would destroy the system. if you believe it's possible you shouldn't support Bitcoin in the first place  - collusion would be possible to the detriment of all coin holders.