Dan provides some good insight on this. Lighter is better.
I have the 21mm Progress Tech (SCA) bar, while not being the lightest bar it is strengthened to that of a 22mm bar.
Only con to AAM bar is that bending the brackets is a chore. With adding any larger bar it is ideal to replace stock mount with weld in brackets and upgraded brackets. After I bent my brackets to mate to the larger 21mm bar I experienced clunk relatively soon as the brackets failed. I replaced my stock brackets with Ford part and pried them up and over the bushing to make a nice tight fit. These lasted about 3 months before I bent them again. People with the Aussie bar have reported failure relatively fast, some not at all. I personally think bending the bracekts causes rapid failure.
Whatever bar you choose, I strongly encourage you to buy the upgraded backing plates and have them welded in. If Aussie is providing the Prothane upgraded brackets that mate to the backing plate you can buy seperately, Aussie bar may save you some cash later. Damn Prothane kit is $10 + $10 shipping. Sticking it to me!
Mine are on order from Aussie.
