I would agree with Neal. Also if the grade of stainless is 304 or 316 it will crack due to work hardening from the heat cycles. I think titanium will do the same.
Proper exhaust stainless (a low carbon grade) would be ideal but it is not cheap.
The Jolly Moto's come with a heat resistant coating to stop rusting.

That's my 2 cents for this year.