Thanks for the link Kent. It was very informative, however, it didn't answer my question.
I have found and corrected the problem that cause the current cat to go bad (a leaky fuel distributer) and I don't want to cut and weld another $50 universal cat on it.
At the same time, I want something of decent quality, that will install easily and last more than a couple of years.
With that being said, I don't have the funds, nor do I believe the car is worth the $1000+ cost of a genuine Mercedes cat. The car itself only has a trade-in value of ~$1000 as it sits.
Anyway, as I'm pressed for time, I'm gonna go ahead and get the DEC branded direct-fit and I'll post my results here about the install and test result impressions.