Here is going to be my honest opinion on the stone wall.
I am and would be reluctant to permanently affix anything to a stone wall.
In my opinion it would ruin the looks of the wall for future people or what ever.
You would have ugly rusty studs sticking out.
If I were to do it I would use stainless studs so they would last one heck of a lot longer.
This isn't Hadrians or Antonine wall is it.
It to me would be a better option to put up posts in front of the wall to put the trellis on.
I have seen this done with pipe bent around the shape of old stone walls and the wire webbing put on it.
A pictuer of the wall would be of great help.