Just a thought, but do you think you'll be lightening up any of the valvetrain at all? You can raise your redline by doing that. I read somewhere on my home forum that for every gram you losein the valve train you get somethin' like 100 extra RPM. Something like that. More RPM means more power of course and with a turbo application, you can rev it quicker and higher to combat turbo lag.
Stiffer valve springs would help. I also read that titanium is good but not for DDs since they wear out sooner.
Just some food for thought for you.