Catalytic converter for my 04 H2

Hi guys im all new in here,
 
I have some few stuff done to my hummer  i'll list them later but for now im facing a problem with my stock catalist .. the engine light is ON.. and I took it to the dealer they said the catalytic converters need to be replaced and they have them really expensive there since my warranty is off now..
 
I have been searching for a good catalic converter but cant seem to find except those universal ones..
 
so can you please help me find the best one ? and also the one that will bolt on.. I dont need welds and stuff unless I really have to weld some.. 
 
I was looking at magna flow cats and they look very good.. except I wasnt a pro to choose on my own..
 
so please help
 
thanks in advance
 

have you find one? well, there are lots of choices that you can choose from.. really depends on what kind you want plus the $$$ you're willing to spend on one.. when my friend had to replaced his old gmc catalytic converter with a new one, he bought an OEM.. and it works great. :)