They dont make an after market header for the b2600i's as far as i know or at least i have never seen one or found one. But if someone can prove me wrong i would be happy since it would be nice to be able to purchase a header for the b200i's.
I'm pretty sure they made them.I think my friend has one.He might even sell it.He is mooneyes1 here on streetsource.Message him. He's pretty much the authority on Mazda's as far as what options they had and who made what for them. Good luck.