Here is the deal on the headers. there just is not a good solution out there they all crack. I have had my ssis on for 6 months with great sucess. They are made of 321 and 347 and are wonderfully built. What I am doing is completing the kits from ssi so that they will be bolt on solutions and will outlast anything out there currently. many guys love them and I do..
as to the gt35 pm one of the guys on the forum running them infact onguys screen name is gt-35r I believe.
As to the KKK turbo's I just think there are better options.
Greg@tialsport.com is a major p-car guy and can set you up perfectly. he is the owner so a bit hard to get ahold of but he can help