vagabond,
1) Skunk got no extractor. Skunk2 got a race exhaust at 70mm piping. But if i not wrong it is for the USA RSX and comes with a 2.25" collector.
Options are J's Racing Japan exhaust system in either 60mm street system or 70mm race exhaust.
For Extractors, J's Racing Japan is coming out soon with their race extractor. Other option is to get custom extractor from USA for you.
2) Skunk2 is finalizing their new design and testing on their new composite intake manifold. Skunk2 does not make air filter system. J's Racing is finalizing their air filter system but no release date yet.
We have the very popular USA velocity stack with custom size 6" K&N filter. All you need is to make a custom 3" aluminum piping. Proven in USA with good top end power.
Have you seen the J's Racing Bodykit for DC5?? It looks awesome man.. :)