It seems that there is always a lot of :cat: swapping going on around inspection time so I thought I would pass a long a find from Summit Racing. I was searching through the Miata specific parts to see what they carried and saw MagnaFlow Direct-Fit Catalytic Converters
for both 1.6 and 1.8 Miatas for $73.95. The picture implies that they come with the gaskets too.