Some people have had problems with the flanges on borla headers being warped and causing leaks. You might want to look at @
FT-86 SpeedFactory headers or @
shiv@vishnu openflash headers. The FT-86SF headers have a catted version as well.
People also report that the evo 3 cat back is loud, especially combined with headers. If you'd like something a little quieter, consider the invidia q300 or Perrin resonated cat back.