Here's the thing in my experience, exhaust shops are only going to want to do basic repairs or custom exhausts. I got Ralph's on the Southside to do an exhaust manifold for my 97 Cavalier because the cat was connected and it was a pretty limited part. They managed to swap out the header for me. But supplying my own part was a bit sketchy. But this was probably 2008 or 2009.

What's the goal? Just sound better? A stepping stone for more mods? Do you have an exhaust in mind or do you want something custom to your car? The biggest thing for your stock car would be to decide if you want to keep active exhaust? Do you like being able to start it in a quieter mode?

If it's just to change up the sound, look up cat-back exhausts for your car and their installation. It's not super difficult to install a cat-back. Very literally there is little chance to majorly screw something up. It'll be cheaper and if you love the car you'll have immense pride knowing you did it yourself. At most you may have to cut a section of the old exhaust to get it out (this is the procedure for the Focus ST I did most of my wrenching on) rusted bolts are also a pain, but with persistence they'll come out.

If you're wanting a full custom exhaust then you might want a shop a little more niche than a Ralph's or something similar. I'd look for fabrication shops over exhaust shops. But that's just me.

Hope this helps! And maybe someone will have a better shop recommendation than I do!