I'm not a fan of plastic

I'm not a fan of plastic handrails either.  One of the problems with athearn Genesis, Atlas, and some others is that the shell above the walkway comes off and leaves the walkway behind.  I prefer the old Athearn blue box method where the whole shell comes off and leaves the chassis.  My recommendation is to absolutely finish everything on the loco as possible, then install the pre-painted handrails.  I like Smoky valley, but either SV or Athearn stanchions work fine.  You mentioned .020 music wire.  I would use .015 brass instead, and solder (best) or CA the stanchions to it.  If you want true scale handrails, you will have to use .012, but I find that thin to be too fragile for my tastes, and the .015 is a good compromise.  Pre paint the handrails with a brush or better still, and airbrush before installing them.

I hope this helps

be thankfull....

Be thankfull that you are not an N Scaler....We have been living with plastic handrails for over 30 years. I recently broke the handrails on a Kato built Atlas U25B, and fortunatly, Atlas still stocks them, but I have to come up with $10 worth of parts that I want to get the handrails that I need.....