Also, I have not seen a powder coated vibration dampening unistrut clamp yet. Please show me one, that would be an interesting, and bad design.
I have seen the green painted (possibly powder coated) unistrut channel, but once you cut it, you should touch up the paint to prevent rust. I just use the stainless 304, it is fairly inexpensive and you never have to worry about customers calling for rust issues in the future.
Repair work, and simple installs, the 304 stainless is just fine. For major construction jobs, the use of less expensive materials would make sense.
And how to mount to stucco? Not sure why you couldnt answer that yourself. A simple wall anchor, toggle bolt, find a stud, ... do I need to add how to mount stuff to walls to my training seminars?