Typically I would paint the stanchions in grey or in your case black and just use the beadalon wire as it is as real stanchions wouldn't be in brass. As regards the RB stanchions (11mm high) these are the best you can get and are CNC machined but the supply is limited due to issues with getting goods out of the EU. Be aware there are also two types for our 1/96 scale RB 074113 (equal spaced which are as rare as hens teeth) and RB 074113B which are unequal spaced which are the ones Deans Marine has. There are also other sources on e-bay which you may want to investigate.
Unequal spaced means there is a bigger gap between the top rail and the lower two. It depends on the ship and when it was built and photo's will guide you.
I tend to "bling" my models a little to add interest by having searchlight rims in brass and a few smaller fittings and perhaps leaving grab rails in brass, binnacles and similar bridge instruments. I tend to paint them in satin varnish to protect them and also so they are not too bright, just catches the eye.
For the wire I use fly fishing swivels as turnbuckles (they are very small, and fly fishing crimps to join the wire. They are black very thin copper tube. Cut it into lengths of about 4mm thread the wire through, round the fitting and back through the crimp. Adjust and then put a spot of superglue on the joint and slid it up tight then cut the tail off. It works well and is quite neat.
Cheers
Geoff