I can only help out with anyone who is waiting for used parts. I have no control (and neither does Keith) on down pipes and intercoolers as he is at the mercy of the suppliers of the parts.
As for the person who started this thread....
All of Keith's down pipes are mandrel bent. The exceptions would be:
Turbo Trans Am pipes
Hot Air pipes
3.5" in custom down pipes
The above 3 do utilize mandrel bent elbos, but they do require some cutting and welding on his part to fit the application.
What you are seeing on your pipe is quite common on many mandrel bends and it is not something that is possible to eliminate. Terry Huston experienced the same issue of minor dimples or waves on the bends. If you were to buy a new exhaust system from Flow master, Walker, Borla, etc you will see the same thing on many of their bends as well and they are at the mercy of the people who bend their stuff as well. This becomes more common the large in diameter the pipe becomes.
If you are that anal about them, then I suggest trying something different.