I've done the K&N cold air, exhaust and the Hypertech max energy. Is there anything else anyone has tried. Hedders maybe any advice??  

Headers will give you some gains but the ones you have already installed did most of the work squeezing out more HP. Headers do and will improve your performance but they come with a high price tag. This is just me talking but I would check into a N20 system. You can safely spray a little nitrous into the motor and see great seat of the pants power. I had a system on my Tacoma and had a blast when that stuff kicked in. I only sprayed a 50hp shot, but you could really feel it when it engaged. I wouldn't over look headers but compare the gains vs price and see if its worth it to you. Also I don't know your budget but a supercharging system would really put a hurt on your rear tires...

-Calin  

Thanks for the advice, I will do some price comparasons and decide.

Craig