What kind of plans horsepower wise do you have? If there are plans of a bigger turbo and probably 350 or more whp. Then you might as well get a FMIC. If you're looking at staying 350whp or less. Then you might as well just get a Process West TMIC or Perrin TMIC. Something like that. I'd be looking at a Cobb BOV, Turbosmart BOV, or Go Fast Bits BOV. But, even then I'd just go full recirculation if its possible. The cars boost system was made to stay a closed loop system.
Alright, anyways...the header question. You will definitely need a tune for headers and the GT Spec UP that comes with the kit. What kind of tune do you have now? I'm hoping that you're tuned already with all those mods installed.
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae