When looking into exhaust and header i knew i wanted either dc or greddy, i hear they're the best from everyone i know, a few guys i work with tell me that dc is better, but i hear from another guy with a lude si that the greddy evo catback system is great too, is the greddy evo better than the dc sports for an h23, and i see a lot of people with the dc sports header, is that better than anything out there? also, 4-2-1, or 4-1?