I have both in my tank for several months and no problems. But be aware that the Amanos will steal all the loach pellets and carry it off to eat. So make sure there are enough for everyone.
They get too big to worry about with kuhlis. Observe how confused this peacock gudgeon is over the size of the amano shrimp.
I imagine it's thinking something along the lines of, "You HAVE to be kidding me with this thing, right?"
Edit: As TMaier was saying, the amano did grab the wafer and try to run away with it