#2 is sound,Accurate and balanced overall,with a little bit more bass presence than that on the high end for the cello.
#3 is durability. Like I said,metal shop. So it might get dinged from time to time.
Thanks in advance.
The Help/Recommendations forum would be a better place for your question, but as I am online now, I can give some suggestions.
For isolation, you should look no further than Etymotic, depending on your budget they have various models.
The "HD Safety" model is specifically made for your work environment, it is reportedly to have the same sound as the Ety Kids 5 so you can look up reviews for that. They should satisfy #1 and #2 but perhaps not on the bass, but if your audio player has an EQ function, then that may solve it.
There is also the Hifiman RE-400, it's bass is slightly above neutral but isolation will not be as good as the Etymotic, but still very good.
But no idea on #3 durability as I have not worked in a metal shop.
BTW, you should only bump your own thread once every 24 hrs if there is no reply from other users.