I did look at other axles prior to doing the Speedway. None of the donor axles were even remotely close to the width I needed, which was 52" to the outside edge of my tires. My car is so small that I quickly realised I needed to go to an axle that was either custom, or a tube axle that could be safely narrowed.
I then began looking at what could be purchased and would be the exact width I needed without cutting it down. All the makers I spoke to were in the $350-$500 range for a custom width. I then talked with them about the various steering brackets, tie rods, joints, etc. and found that they usually either sent me towards a used source, or a second vendor to buy the rest the spindles, brackets, etc. Often the vendor they sent me towards was Speedway for the rest.
After going through the options, I decided it was easier, cheaper, and less hassle to so to Speedway and get all of the parts as a kit and narrow the axle. I welded two pieces of angle iron on the main tube to retain the kingpin alignment, then cut 6" out of the middle of the tube. After that I got a 12" piece of shaft from a conveyor assembly and pressed it half into each side of the main tube. I left it about .5" apart in the middle and that was welded up to surface and turned down. It added some unsprung weight to the axle, but kept it strong.
Once it was welded up I cut the angle iron off the tube, ground it smooth and installed it under the car with 7 degrees on the king pins. It tracks straight at freeway speeds, and corners well too.