Good thread. I have been wondering the same things about the same brands. I am super happy we have these options so soon for this car. But it does make deciding very hard!!
We need more threads like this. Very helpful:
http://www.ft86club.com/forums/showthread.php?t=31555
Unfortunately it is hard for any one company that is not already selling a header product to have access to all the available header options and do dyno comparisons on the same dyno with the same car.