i bought a stainless set for my 392 at a swap. the guy modified the collector area for some reason [he said they hit the oil pan ?], but i will be doing further mods because of what i want to do.
plus, i got them for a great price.
stainless will, however, discolor, so keep this in mind. six of one, 1/2 a dozen of the other.
then, there is the "it depends" on the coating. i have seen some coatings that are crap, while others last many, many years without issues in color or bonding.