jeebus @ mmw
+1y
Sway bars are made from spring steel, its not an ordinary round bar you can buy everywhere, its a special kind of material. Welding to it is also something that would need to be done with serious caution and skill.
using just a regular 1018 CR MS round bar would do nothing as a sway bar.
Best bet is to adapt to a kit that is all ready produced within your parameters, or spend the big bucks on a custom one.