Ill write in english because my swedish isnt that good

Im in desperate need of a new cat for my Celica ST202 because at the yearly checkup they didnt really like my rusty exhaust, and the exhaust part is fixed (brand new HKS Silent Hi-Power system) but i simply cant find another cat for the car. I could buy a new one from Toyota, but they seem to think that its gold they got, so if anyone have a used stock cat laying around i would be very happy to know that.
Best Regards
Kenneth