What adhesive is best to glue strain gauges to metal?
I have experience with two-component HBM X60 glue specially made for strain gauges. It's quite expensive, but i can tell, it withstands a lot.  

But in general, i would say that any kind of fast cyanoacrylic glue would suit your needs. I have tried 350 ohm, one axis strain gauges with cheap cyanoacrylic glues which you can get on every corner, and it worked well.