I guess they mixed it up damn good between the U.S and Euro market..I searched around on a scrapyard homepage and found 325i E90 with the same typ of headers you are refering to.
But if you have issues with passing smog inspection with removing the cats in the headers, just keep the secodary cats and mount a 300 cell cat where the stock resonator sits on the OEM exhaust! It will still "clean" the exhausts but give alot less resctricion back there where the exhaust gas has lost alot of its heat and volym. Only diff is that due to the colder inviroment it will be placed in it will take more time to get it heated up to opptimum working temp. But just do acouple of hard pulls before inspection adn it will be find... That how we do over here and we run singel 100cell cats
EDIT: found out now that we have totaly diffrent airbox aswell....
I picked up a used "euro box" for $70 to day for modding to a DIY CAI..