http://www.rockler.com/large-diameter-dowel-rods-3-dia

You can order 3 inch diameter rods here. Any metal fabricator can "wrap" a piece of wood in brushed SS.

Horizontal railings are not to code in many places you should check that out and yes there are maple rods and stainless rods

Your guardrail can't be a ladder for children to climb. Anyone can dream up and/or draw anything. The difficulty is great design within the parameters of the building code. That takes talent.

There are NO restrictions on whether or not a guard rail meant to protect against accidental falls can be climbable in the IRC (US building codes) because they are smart enough to realize that a chair can be placed next to the railing making it easy to climb over regardless of the design of the rail.

(Yes, even in Florida, Joseph)

http://floridabuilding2.iccsafe.org/app/book/content/2014_Florida/Residential%20Code/Chapter%203.html

The rail is there to prevent accidents, NOT stupidity. Canada is the only place ridiculous enough to play big brother to that sort of thing, but they have also mandated lever knobs for all doors, and will soon require padding on all the walls, floors, and ceilings of the rooms, and no projections that you could tie a rope to for hanging yourself ;D

That railing would not pass code in many places