Well, you could do what I've done.  Fabricate an exhaust from stainless
tubing, then ceramic coat it (for heat retention).  I coated the stainless
mufflers and cat too.  The coating has been there for 2 1/2 years now, and
no sign of flaking.  I did have a problem with the CAT internal element
breaking up, but I'm fairly sure this was a manufacturing issue as it
failed within 1000K, and the replacement (also ceramic coated) has been on
for another 7000K of hard use (towing a trailer, loaded Westy) with no
problems. Because I applied it myself, I can attest to the value of
sticking to the manufacturers prep.  Sandblast, clean with lacquer thinner,
coat.  They are very specific on re-coating (you don't) as well as dry/heat
cure times.  Truthfully, I've never seen a coating of any kind perform this
well on an exhaust system.

I've had a stainless Techtonics system on my daily driver (salty winters
too) for 10 years now...the same exhaust.  It still looks great.