As far as I know, nobody makes a 2.5 inch mandrel bent exhaust for staggered shock cars. Pypes makes them for non-staggered shocks, don't know how difficult it would be to modify them, been hoping someone would give it a try.
I've been thinking about one of the kits that comes with all of the bends and straight tubing and using my 2.25" exhaust as a pattern and cutting/welding up my own.
Some of our members have found local muffler shops that have reasonable prices. There is one near me that does mandrel bent stainless for a not too bad price.
Edit: Because of all of us having to use unleaded gasoline, there is one benefit, and that is plain steel exhausts last much longer, and aluminized for even longer. The compounds in the lead additive actually created a mild acid that promoted rapid rusting.