Aquamist is the pinnacle of the W/M injection systems and the HFS-3/4 are the newest design systems with comprehensive fail safes built-in. AM can run mixtures from 100% water to 100% methanol without any ill effects on the components. Of course nothing will save you from Murphy's law, but this is as good as it gets.
I have a slightly used HFS-3 with trunk mounted tank/pump from Howerton Engineering for sale. It has been on my race car for some time and it did it's job exactly as intended, saving my engine on a few occasions. I now run E85 so it is a good time to get rid of ~10lbs.