You can probably get all the parts from a shop catering to diesel trucks or a muffler shop that works on them. Nothing special about the parts. Most likely it's 4in tube. You might take the old one off and take it with you to match the bends. I would replace the clamps while you are at it.
Bill
2008 Newmar Mountain Aire
450 HP CUMMINS ISM
ALLISON 4000 MH TRANSMISSION
TOWING 2014 HONDA CRV With Blue Ox tow bar
A man who carries a cat by the tail learns something he can learn in no other way.
-Mark Twain