McCracken, I think stainless is good for the dump as it has better high temp resistance, but they can crack. I can't remember what grade doesn't crack... inasnt, wanna help us out on this one?
Just a note also, bear in mind that cost is one thing; i would much rather spend the extra 20/30/40 bucks if it guarantees that the flanges are flat, it doesn't touch the body, doesn't rattle etc etc. That is mainly the reason i got a jap exhaust. This is not to say the local product is no good, just look at inasnt's exhaust - custom made and fine.