I went through this last year on my 92 M998 when I had to remove (most) of the system to upgrade to a 4L80 tranny and the exhaust disintegrated in my hands.
Performance options? Nah - you don't need ANY stink'in performance options. You drag racing your rig?
- You might be able to find an old rusty stock system os fleabay or FB, pay an arm and leg, and have the same problem in a year or so.
- You can have an exhaust shop make you up something aftermarket that will work. Depending on your area and the shop willing, you still might pay almost an arm and a leg
- You can shop around for the stock components and pay an arm and leg
There is no magic.
Be aware that there are two different cross over pipes, the ones that come out of the manifolds, that evidently look identical but are slightly different width for the turbo vs. NA. I did not know and I lucked out and happened to get the correct one but other forum members were not so lucky.
I ended up looking around for NOS and NIB stuff and just bit the bullet. I did paint it with some high temp primer and silver paint so it won't rust as quickly.