Nobody is laughing at me.
Cosworth headers are very nice, but the primaries are slightly bigger than I would want. They will be fine and won't be a problem, but they are intended to be capable of working on a balls out NA engine. I just bought one about a week ago to see how their header is, and after putting it on the other day, I can say that esp. from 3-7k rpms, this thing sings. It goes up much faster and much smoother.
It is quite loud and smells perfect now.
We are going to the track this weekend. Expect times. Expect 14s if the weather cooperates.
I'm going to start playing with my manifolds and stuff very shortly, and hopefully I can do some good..lol.
Honestly, if you aren't seeking retardulous gains, a draxas would be enough header for most people, esp. on a d20. Start with a good intake (marcy, focussport, F2, etc) and an exhaust system (depending on your local noise situation. An STS is a MUST. Throttlebodies don't give much in the way of power (within the error of margin on a dyno) and are mainly a throttle response modification. Suspension mods are great (but you will be waiting a few months on an 06) and the xcal2 tuner is also recommended down the road.