Take a look at Devil's own products as well, I run their stage 2 progressive kit on my WRX with great results. I don't / will not run meth on my 1M as I will not be tuning on higher octane. If you're just looking for additional safety you can always just run 100% distilled water and a stage 2 map.
If you ARE going to tune on meth in your 1M I highly recommend some sort of mechanical fail safe. Something that physically sits in the meth line and monitors water flow with the ability to pull the waste gates when out of operating range. Anything at the ECU level or electronically sampled is probably going to react too slowly to prevent damage. Motors on this car are expensive, don't blow it up.
AEM makes a product that should do the trick, here is a PDF