[s-cars] Cat replacement options?

[Gary]

So my wife (who's the primary driver of our '94 S4) came home from work
yesterday to tell me that the UrS feels "constipated" and "not as fast
as when we bought it."

It certainly feels to me like the cats are partially plugged and the
fact that it ran with an ignition misfire for a while earlier this year
probably helped them towards their demise.

Is there any list wisdom for sources for replacement cats?  I'm
certainly not a fan of letting the local Midas shop attack it with a 
torch and a couple of generic converters, but I'm guessing direct 
replacements that I could install myself in the garage would run more 
than a full Stromung.

We are in an area that performs emissions testing with visual inspection
every two years, so just yanking them isn't a great option.

Suggestions appreciated!

-Gary

P.S.  I'd consider a Stromung, but I thought I recall somebody telling
me they weren't being manufactured any longer.  If I'm wrong on that,
would somebody please forward me Jeff P's email addy?