Since you already have the vibrant exhaust I say go with the header. That way you know they will fit and that they were developed to work together.vibrant to match wid ur exhaust =]
Yes...I'm a newb and not a mechanicGo Vibrant! They have great products and great support. Plus you already have part of the Vibrant equation. I have the RH w/Cat and it is great. Quiet when you want it, loud when you want it.
Either way make sure you wrap it with DEI or other wrap and then spray the coating. This makes a huge difference in performance as it increases the scavenging effects of the header. Which is why you are buying it in the first place!