PRP's. Like has been said, go see Pat at Those Guys and try on the different models before ordering. One other nice thing about PRP is if you can imagine the color or material, they will do it.
Look up the Stancore relay mod, lots of info about it on Powerstroke.org and Powerstrokenation.com. That being said, I have 3 years on a BWD unit from Schucks/O'reillys
Opacity test, they aren't even checking the co, co2, or nox. If you don't smoke, you'll pass every time. That reminds me, I need to dial my tuner back before I go test.:mad:
They can/will only check for missing emmisions equipment if going for an emmisions waiver. If it'll pass emmisions and there is no check engine light on, you can get away it.