I would make my own sway bar, if I felt like rebuiling the CAR after the bar had failed. It will usually fail when you are deep in a turn, all crossed up, and leaning heavily on the suspension.
Using the wrong material and wrong techniques can create a bar that may suddenly break, or slowly bend. It will do that while you try to identify why the handling is changing on you. And, you will typically, in your analysis of the problem, be chasing every suspect component except the sway bar.
Take the advice of R.J and Jay, and buy the 3 piece modular bars. They are easliy tunable, strong and consistent.
I hate dodging a spinning car in front of me when they have had a sway bar suddenly snap or fail....