I would, emmisons are way easier here. Just opacity. Or if you're lucky, you can register outside of Maricopa or Pinal to avoid emmisions altogether.
I know the ebay listing says not for sale in California and New York. As of January 21 that applies to Colorado as well unfortunately. As for the wrecking yard... it is illegal to resell catalytic converters in the state of Colorado. I have looked into all of these suggestions quite thoroughly as this is not the first vehicle I have worked on or had to do emissions certification on. This is however the first cummins diesel I have had to do this for and Colorado doesn't screw around apparently. I'm honestly considering flying to Arizona and just registering it there for 58$ round trip.