As others have said, there are no good aftermarket direct fit replacements available. The DEC and A&B are worthless, with a max life of about two years. Most of the people I know who've installed these things say that they come back within a few months, and they tend not to pass HC emissions test to begin with.

The OEM cat isn't expensive when one considers that they last ten to fifteen years.

Personally, I'd weld in a carsound magnaflow and be done with it.

best, whit